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A2 adjective #2,000 most common 9 min read

insistente

Top 2,000

Practice it Examples Notes & Tips insistente in 30 Seconds

Explanation insistente in your Level:

At the A1 level, you should understand 'insistente' as a word used to describe someone who says the same thing many times. Think of a child asking for a toy or a friend asking you to go out when you are tired. It is an adjective, which means it describes a person or a thing. In Portuguese, 'insistente' is special because it is the same for men and women. You can say 'Ele é insistente' and 'Ela é insistente'. You don't need to change the ending. At this level, you might use it in very simple sentences like 'O meu amigo é insistente' (My friend is insistent). It is a useful word to know when you want to talk about people's behavior in a simple way. You might also hear it when someone is talking about a phone ringing many times. 'O telefone é insistente'. It helps you describe a situation where something doesn't stop. Remember that it comes from the verb 'insistir', which means 'to insist'. Even if you don't know many words yet, 'insistente' is easy to remember because it looks like the English word 'insistent'. This makes it a 'cognate'. Use it when you want to say that someone is not giving up on what they want. Just be careful with the pronunciation: the 'in' is like a nasal sound, and the 's' sounds like a 'z'.

At the A2 level, you can start using 'insistente' in more varied contexts. You should know that it can describe not just people, but also things like sounds, smells, or weather. For example, 'chuva insistente' (persistent rain) is a very common phrase you might hear in a weather report or read in a simple story. You should also be able to use the plural form, 'insistentes', by adding an 's'. For example, 'Eles são muito insistentes'. At this level, you are learning more about how adjectives work with different verbs. You can use 'ser insistente' to describe a personality trait (He is an insistent person) or 'estar insistente' to describe how someone is acting right now (He is being insistent today). This is a great way to show you understand the difference between 'ser' and 'estar'. You might also start to see 'insistente' in simple news articles or advertisements. For example, 'uma oferta insistente' (an insistent offer). It is a good word to use when you are complaining about something in a polite way, like 'O vendedor foi muito insistente'. This level is about expanding your ability to describe the world around you, and 'insistente' is a perfect tool for describing repetitive actions or persistent situations.

At the B1 level, you should be comfortable using 'insistente' in more complex sentence structures and understanding its different nuances. You can now distinguish between 'insistente' and its synonyms like 'persistente' or 'teimoso'. You know that 'insistente' often implies a verbal or active demand, while 'persistente' might be more about long-term effort. You can also use the adverbial form 'insistentemente' to describe how an action is performed: 'Ele pediu insistentemente para sair'. This level requires you to use the word in professional or social settings with the correct tone. For instance, you might describe a 'problema insistente' in a work report, meaning a problem that keeps coming back despite attempts to fix it. You should also be aware of common collocations like 'olhar insistente' (a lingering or insistent look) and how they can change the mood of a sentence. In terms of grammar, you should be able to use 'insistente' with relative clauses: 'Aquele é o homem insistente de quem eu te falei'. You are also starting to recognize the word in literature and more advanced media, where it might be used metaphorically. For example, 'uma lembrança insistente' (a persistent memory). Your goal at B1 is to move beyond simple descriptions and start using 'insistente' to express more subtle ideas about behavior and persistence.

At the B2 level, you have a deep understanding of 'insistente' and can use it fluently in both formal and informal Portuguese. You understand that the word can carry a heavy emotional weight or a specific technical meaning depending on the field. In a legal or business context, 'insistente' might describe a type of solicitation or a recurring demand that has legal implications. You are also able to use the word to create specific stylistic effects in your writing. For example, you might use 'insistente' to describe the rhythm of a poem or the atmosphere of a scene: 'O tic-tac insistente do relógio aumentava a sua ansiedade'. You can also handle the word in idiomatic expressions and more abstract contexts. You understand the cultural nuances of being 'insistente' in different Lusophone countries—for example, how persistence is viewed in Brazilian business culture versus Portuguese social etiquette. At this level, you should be able to argue whether being 'insistente' is a positive or negative trait in a given scenario, using a wide range of supporting vocabulary. You are also proficient in using the word with various prepositions and in complex grammatical constructions, such as the passive voice or the subjunctive: 'Duvido que ele seja tão insistente quanto parece'. Your use of 'insistente' is now natural, precise, and contextually appropriate.

At the C1 level, your command of 'insistente' is near-native. You use it with a high degree of precision to convey subtle shades of meaning. You are familiar with its less common synonyms like 'pertinaz' or 'assíduo' and know exactly when to use 'insistente' instead to achieve a specific rhetorical effect. You can analyze the use of 'insistente' in classical Portuguese literature, recognizing how authors use it to characterize figures or build tension. In your own high-level writing, you use the word to describe complex psychological states or intricate social dynamics. For example, you might write about 'a insistente busca pela identidade' or 'o caráter insistente das desigualdades sociais'. You are also fully aware of the phonetic nuances and can use the word in public speaking or formal presentations without hesitation. You understand the word's etymological roots and how they connect to other words in the 'insistir' family, allowing you to manipulate the language creatively. At this level, 'insistente' is not just a vocabulary word; it is a versatile tool in your linguistic arsenal that you use to express sophisticated thoughts with clarity and elegance. You can also identify and correct subtle misuses of the word by others, showing a mastery of both the rules and the spirit of the Portuguese language.

At the C2 level, you possess a masterly command of 'insistente' and its place within the vast landscape of the Portuguese language. You can use the word in the most demanding academic, literary, or professional contexts. You understand its historical evolution and how its usage has shifted over centuries of Portuguese writing. Your ability to use 'insistente' is characterized by an effortless precision; you can deploy it in a philosophical treatise to describe 'a vontade insistente' or in a highly technical medical report to detail 'uma sintomatologia insistente'. You are also sensitive to the most minute regional variations in its usage across the entire Lusophone world, from Maputo to Macau, from Lisbon to Luanda. You can play with the word's connotations, using it ironically or metaphorically to add layers of meaning to your discourse. At this level, you don't just know the word; you inhabit it. You can discuss the word's relationship with concepts like 'resiliência', 'obstinação', and 'perseverança' with the depth of a linguist. Your use of 'insistente' is indistinguishable from that of an educated native speaker, reflecting a profound connection to the cultural and intellectual heritage of the Portuguese-speaking world.

Practice it Examples Notes & Tips

insistente in 30 Seconds

Insistente means persistent or demanding, used for people who don't give up easily on their requests or actions.
It is a gender-neutral adjective in Portuguese, ending in -e, and its plural form is insistentes.
Commonly used for people (salespeople, children) and environmental factors (rain, noise, smells).
Can have a positive (persevering) or negative (annoying) connotation depending on the context.

The Portuguese word insistente is an adjective that describes someone or something that persists in a specific action, demand, or state, often despite resistance or lack of immediate success. It is derived from the verb insistir (to insist). In a positive light, it suggests perseverance and determination; in a negative context, it can imply being annoying, nagging, or intrusive. Understanding the nuance of insistente requires looking at the intent behind the persistence. For example, a student who is insistente in their studies is seen as dedicated, whereas a salesperson who is too insistente might be viewed as bothersome.

Core Concept: Repetition of an action or request with the goal of achieving a specific outcome.

O barulho insistente da chuva no telhado não me deixou dormir.

When applied to people, it often refers to their communication style. An insistente person doesn't take 'no' for an answer easily. This can be a vital trait in negotiations or activism. However, in social settings, being overly insistente can strain relationships. The word is also frequently used to describe physical sensations or environmental factors, such as a persistent cough (tosse insistente) or a recurring thought (pensamento insistente). The linguistic root links back to the Latin 'insistere', meaning to stand upon or pursue eagerly.

Synonym Focus: Persistente (Persistent) is the closest synonym, but 'insistente' often carries a stronger connotation of verbal demand.

Ela foi muito insistente e acabou conseguindo o desconto.

In Portuguese literature and daily news, you will see this word used to describe political pressure, marketing campaigns, and even weather patterns. It is a versatile word that fits both formal and informal registers. When you call someone insistente, you are highlighting their refusal to yield. It is important to note that the word does not change for gender (o homem insistente / a mulher insistente), which makes it easier for learners to use correctly in various sentences.

Recebi várias chamadas insistentes de números desconhecidos.

Usage in Health: Medical professionals use it to describe symptoms that do not go away, like a 'dor insistente' (persistent pain).

A febre insistente preocupou os médicos.

Ele tem um olhar insistente que me deixa desconfortável.

Using insistente correctly involves placing it after the noun it modifies in most cases, following standard Portuguese adjective placement. Because it ends in '-e', it is a uniform adjective, meaning it stays the same regardless of whether the noun is masculine or feminine. For example, 'um pedido insistente' (a persistent request) and 'uma pergunta insistente' (a persistent question). The plural form is insistentes.

Grammar Rule: Uniform adjective: does not change for gender. Pluralized by adding 's'.

Os vendedores insistentes foram proibidos de entrar no prédio.

In terms of intensity, you can modify insistente with adverbs like 'muito' (very), 'extremamente' (extremely), or 'bastante' (quite). If you want to say someone is 'too' insistent, use 'demasiado' or 'excessivamente'. This is common when complaining about telemarketing or unwanted attention. Conversely, in a professional setting, being 'adequadamente insistente' (appropriately insistent) might be a praised quality in a project manager.

Common Collocations: Chuva insistente, pedido insistente, ruído insistente, olhar insistente, busca insistente.

A busca insistente pela verdade levou anos.

When describing a person's character, you might say 'Ele é um homem insistente'. If you are describing a temporary state, you would use the verb 'estar' (to be temporarily): 'Ele está muito insistente hoje' (He is being very insistent today). This distinction is crucial in Portuguese to convey whether the persistence is a personality trait or a situational behavior. In writing, insistente adds a layer of rhythm and weight to descriptions of sounds or recurring events.

O despertador tocava de forma insistente.

Adverbial Form: The adverbial form is 'insistentemente' (insistently).

Ele bateu na porta insistentemente.

Não seja tão insistente, ela já disse que não pode ir.

You will encounter insistente in a wide variety of daily situations. In the news, it's often used to describe diplomatic efforts or public demands: 'A pressão insistente da população levou à mudança na lei'. In the workplace, you might hear it during meetings or performance reviews: 'Precisamos ser mais insistentes com nossos fornecedores'. It's also a staple in weather reports, especially in regions with long rainy seasons where 'chuva insistente' is a common phrase to describe drizzle that lasts for days.

Media Usage: Journalists use it to describe persistent rumors or recurring social issues.

Os rumores insistentes sobre a demissão do técnico foram confirmados.

In social circles, the word often comes up when talking about dating or friendships. 'Aquele rapaz é muito insistente' might be said about someone who keeps asking for a date. In family life, parents often describe their children's requests as insistentes. 'O meu filho é muito insistente quando quer um brinquedo novo'. It captures that specific feeling of a request that keeps coming back like a boomerang. You'll also hear it in literature to describe the rhythm of music or the ticking of a clock.

Medical Context: Used in clinical descriptions of chronic symptoms.

A tosse insistente é um sintoma que requer atenção.

In the arts, critics might describe a 'tema insistente' in a movie or a symphony. This refers to a motif that repeats throughout the work to create a specific emotional effect. In sports, a commentator might say 'O ataque foi insistente até marcar o golo', highlighting the team's relentless pressure. Whether it's the 'chamada insistente' of a phone or the 'pedido insistente' of a friend, the word is ubiquitous in Portuguese-speaking life, bridging the gap between physical persistence and psychological determination.

Havia um cheiro insistente de mofo no porão.

Business Context: Used to describe aggressive marketing or persistent follow-ups.

O marketing insistente da empresa incomodou os clientes.

O apelo insistente do diretor mudou a opinião da equipe.

One of the most common mistakes for English speakers is trying to change the gender of insistente. Unlike many Portuguese adjectives that end in '-o' or '-a', insistente ends in '-e' and is gender-neutral. Avoid saying 'insistenta' for a female subject; it is always insistente. Another error is confusing it with 'persistente'. While they are often interchangeable, insistente usually implies a more active, verbal, or demanding form of persistence, whereas 'persistente' can be more passive or internal (like a persistent effort over time).

Gender Neutrality: Correct: Ela é insistente. Incorrect: Ela é insistenta.

Maria é muito insistente com seus objetivos.

Learners also sometimes misuse the preposition after the related verb insistir. You insist *on* something (insistir *em*). When using the adjective, you don't always need a preposition, but if you do, it's often 'com' (insistente com alguém). Another mistake is using 'insistente' when you mean 'teimoso' (stubborn). While an insistente person might be stubborn, 'teimoso' is purely negative, implying a refusal to change one's mind even when wrong. Insistente can be a neutral or even positive description of someone's drive.

Preposition Usage: Insistente COM (with) people; Insistente EM (in/on) actions.

Ele foi insistente com o gerente para resolver o problema.

Mispronunciation is another common pitfall. The 's' in the middle is pronounced like a 'z' sound (/ĩ.zis.ˈtẽ.tʃi/ in Brazil, /ĩ.ziʃ.ˈtẽ.tɨ/ in Portugal). If you pronounce it with a hard 's' like in 'snake', it will sound unnatural. Also, ensure you don't drop the final 'e' in European Portuguese; it should be a very short, almost silent vowel, but it's still there. In Brazilian Portuguese, the final 'e' often sounds like an 'i'. Getting these phonetic details right will make your use of insistente sound much more native.

A sua voz insistente ecoava na sala.

False Friends: 'Insistente' is a true friend of 'insistent', but 'instante' means 'moment'. Don't mix them up!

O convite insistente dele foi difícil de recusar.

A crítica insistente não o desanimou.

To truly master insistente, you should compare it with its synonyms and related terms. The most common alternative is persistente. While insistente is often about asking or demanding, persistente is about continuing an effort over a long time. For example, a 'persistente' athlete works hard for years, but an 'insistente' child asks for candy ten times in a minute. Another related word is tenaz (tenacious), which implies a strong, almost unbreakable grip on a goal or idea, usually carrying a very positive, heroic connotation.

Insistente vs. Persistente: Insistente: repetitive action/request. Persistente: long-term endurance.

Ele é um trabalhador persistente, mas não é um vendedor insistente.

Then there is obstinado (obstinate), which is closer to 'stubborn'. An obstinado person refuses to change their course of action even when faced with better alternatives. Pertinaz is a more formal, literary synonym for insistente, often used in legal or academic texts to describe a quality that is difficult to remove or change. On the more negative side, you have importuno (annoying/bothersome), which describes someone whose insistence has become a nuisance to others. Understanding these shades of meaning allows you to choose the exact word for the situation.

Formal Alternatives: Pertinaz, constante, assíduo.

A sua tenaz vontade de vencer superou todos os obstáculos.

In terms of physical descriptions, contínuo (continuous) or incessante (incessant) are often used where insistente might also fit. 'Chuva incessante' is even stronger than 'chuva insistente', implying it never stops for a second. 'Ruído contínuo' suggests a steady hum, while 'ruído insistente' might suggest a sound that stops and starts but keeps coming back to bother you. By expanding your vocabulary with these synonyms, you can describe the world with much greater precision and flair in Portuguese.

O barulho incessante das máquinas era ensurdecedor.

Negative Nuance: Maçador, chato, pegajoso (sticky/clingy).

Ele tornou-se importuno com tantas perguntas.

A sua presença insistente começou a incomodar.

How Formal Is It?

Difficulty Rating

Grammar to Know

Adjective-Noun agreement (plurality)

Uniform adjectives ending in -e

Ser vs Estar with adjectives

Adverb formation with -mente

Prepositional use with 'insistir em'

Examples by Level

O meu gato é muito insistente.

My cat is very insistent.

Adjective follows the noun and verb 'ser'.

Ela é uma pessoa insistente.

She is an insistent person.

Uniform adjective: 'insistente' works for 'pessoa' (feminine).

O telefone é insistente hoje.

The phone is insistent today.

Using 'ser' for a general state.

Não sejas insistente, por favor.

Don't be insistent, please.

Imperative mood (negative).

Ele tem um pedido insistente.

He has an insistent request.

Adjective modifying the noun 'pedido'.

A criança é muito insistente.

The child is very insistent.

Simple subject-verb-adjective structure.

Você é muito insistente!

You are very insistent!

Direct address using 'você'.

Um vendedor insistente ligou para mim.

An insistent salesman called me.

Adjective placed after the noun.

A chuva insistente molhou tudo.

The persistent rain soaked everything.

Common collocation: 'chuva insistente'.

Eles são alunos muito insistentes.

They are very insistent students.

Plural form: 'insistentes'.

Recebi chamadas insistentes do banco.

I received insistent calls from the bank.

Plural noun and adjective.

O barulho insistente vinha da rua.

The persistent noise came from the street.

Adjective describing an abstract noun 'barulho'.

Ela foi insistente e conseguiu o emprego.

She was insistent and got the job.

Past tense 'foi' (pretérito perfeito).

O cheiro insistente de café estava no ar.

The persistent smell of coffee was in the air.

Describing a sensory experience.

Não gosto de pessoas insistentes.

I don't like insistent people.

Plural adjective matching 'pessoas'.

O meu irmão está muito insistente hoje.

My brother is being very insistent today.

Using 'estar' for a temporary state.

Apesar da recusa, ele continuou insistente.

Despite the refusal, he remained insistent.

Using 'apesar de' with a noun.

Havia um rumor insistente sobre a crise.

There was a persistent rumor about the crisis.

Abstract usage in a social context.

O seu olhar insistente deixou-me nervosa.

Your insistent look made me nervous.

Possessive pronoun 'seu' and adjective.

Ele pediu insistentemente para falar com o diretor.

He insistently asked to speak with the director.

Adverbial form 'insistentemente'.

A tosse insistente não passava com o xarope.

The persistent cough wouldn't go away with the syrup.

Medical context.

A propaganda insistente na TV é irritante.

The insistent advertising on TV is annoying.

Subject with a prepositional phrase.

Ela tem uma vontade insistente de viajar.

She has a persistent desire to travel.

Describing an internal state.

O rádio emitia um sinal insistente.

The radio was emitting an insistent signal.

Describing a technical sound.

A pressão insistente dos media forçou a demissão.

The insistent pressure from the media forced the resignation.

Formal/Political context.

O ritmo insistente da música contagiava a todos.

The insistent rhythm of the music was catching for everyone.

Describing artistic elements.

Houve uma busca insistente por sobreviventes.

There was a persistent search for survivors.

High-stakes context.

O seu comportamento insistente foi considerado assédio.

His insistent behavior was considered harassment.

Legal/Professional nuance.

A dúvida insistente corroía a sua confiança.

The persistent doubt was eroding his confidence.

Metaphorical usage.

Eles foram insistentes na defesa dos seus direitos.

They were insistent in the defense of their rights.

Positive connotation of persistence.

A memória insistente daquele dia nunca o abandonou.

The persistent memory of that day never left him.

Literary/Emotional context.

O apelo insistente da ONU foi ignorado.

The UN's insistent appeal was ignored.

International relations context.

A natureza insistente do problema exige uma solução radical.

The insistent nature of the problem demands a radical solution.

Abstract noun phrase 'natureza insistente'.

O autor utiliza um tom insistente para enfatizar a tese.

The author uses an insistent tone to emphasize the thesis.

Literary analysis.

A sua presença insistente nos eventos sociais era notada.

His insistent presence at social events was noticed.

Social commentary.

O zumbido insistente nos ouvidos era um sinal de cansaço.

The insistent ringing in the ears was a sign of fatigue.

Detailed medical description.

A retórica insistente do político cansou o eleitorado.

The politician's insistent rhetoric tired the electorate.

Political analysis.

A busca insistente pela perfeição pode ser paralisante.

The insistent search for perfection can be paralyzing.

Philosophical observation.

Havia uma fragrância insistente de jasmim no jardim.

There was a persistent fragrance of jasmine in the garden.

Evocative description.

O seu pedido, embora insistente, foi educadamente declinado.

His request, though insistent, was politely declined.

Concessive clause 'embora'.

A insistente ontologia do ser é um tema central na obra.

The insistent ontology of being is a central theme in the work.

Philosophical/Academic register.

O caráter insistente das pulsões foi analisado por Freud.

The insistent character of the drives was analyzed by Freud.

Scientific/Psychological register.

A sua prosa é marcada por uma cadência insistente e hipnótica.

His prose is marked by an insistent and hypnotic cadence.

Stylistic analysis.

A insistente reivindicação de soberania gerou tensões.

The insistent claim of sovereignty generated tensions.

Geopolitical register.

O eco insistente da história ressoa nas ruas da cidade.

The insistent echo of history resonates in the city streets.

Poetic/Metaphorical register.

A sua argumentação, de uma lógica insistente, convenceu o júri.

His argument, of an insistent logic, convinced the jury.

Complex noun phrase structure.

A insistente recorrência de tais fenómenos intriga os cientistas.

The insistent recurrence of such phenomena intrigues scientists.

Scientific observation.

A insistente melancolia do fado define a alma portuguesa.

The insistent melancholy of fado defines the Portuguese soul.

Cultural/Sociological register.

Common Collocations

chuva insistente

pedido insistente

ruído insistente

olhar insistente

vendedor insistente

tosse insistente

rumor insistente

chamada insistente

busca insistente

pressão insistente

Common Phrases

Ser insistente

Estar insistente

De forma insistente

Um pouco insistente

Muito insistente

Demasiado insistente

Tornar-se insistente

Continuar insistente

Apesar de insistente

Embora insistente

Often Confused With

insistente vs Instante (moment)

insistente vs Inexistente (non-existent)

insistente vs Inconsciente (unconscious)

Idioms & Expressions

"Água mole em pedra dura, tanto bate até que fura (related to persistence)"

"Bater na mesma tecla (to be insistent on a topic)"

"Não dar o braço a torcer (to be insistent/stubborn)"

"Ficar no pé de alguém (to be insistent with someone)"

"Encher a paciência (to be annoyingly insistent)"

"Moer o juízo (to be insistent/annoying)"

"Ser um osso duro de roer (to be a tough/insistent person)"

"Dar murro em ponta de faca (to insist on something useless)"

"Falar para as paredes (when insistence fails)"

"Não largar o osso (to be very insistent on something)"

Easily Confused

insistente vs

Sentence Patterns

How to Use It

nuance

Insistente is more about the frequency of the action, while persistente is about the duration.

formality

It is neutral and can be used in all levels of formality.

Common Mistakes

Using 'insistenta' for feminine nouns.
Pronouncing the 's' as a hard 's' instead of a 'z'.
Confusing it with 'instante' (moment).
Forgetting the nasal sound of the 'in'.
Using it as a verb (it is an adjective).

Tips

Word Pairing

Always pair 'insistente' with 'chuva' or 'pedido' to remember its most common uses.

Nasal Vowels

Practice the 'in' sound by pushing air through your nose. It's not a hard 'n'.

No Gender Change

Remember that adjectives ending in -e are your friends because they don't change for gender!

Politeness

If you want to tell someone they are being too much, 'Você está sendo um pouco insistente' is a polite way to say it.

Adverb Use

Use 'insistentemente' to add detail to how someone is acting in your stories.

Context Clues

Listen to the speaker's tone. If they sound annoyed, 'insistente' is a negative thing.

Business

In Brazil, being 'insistente' in follow-ups is often expected in professional environments.

Cognates

Use the fact that it looks like 'insistent' to help you remember it quickly.

Stress

The stress is on the second-to-last syllable: in-sis-TEN-te.

Plurals

Don't forget the 's' when talking about more than one person or thing.

Memorize It

Word Origin

Latin

Cultural Context

Persistence is often called 'garra' or 'perseverança', but 'insistente' is the common word for the action.

Being 'insistente' can sometimes be perceived as 'falta de educação' (lack of manners) if overdone.

Practice in Real Life

Real-World Contexts

Conversation Starters

"Você se considera uma pessoa insistente?"

"Qual é o barulho mais insistente que você conhece?"

"Você já teve que lidar com um vendedor muito insistente?"

"A chuva insistente te deixa triste ou relaxado?"

"Quando é bom ser insistente na vida?"

Journal Prompts

Descreva uma vez em que você foi insistente para conseguir algo.

Escreva sobre um problema insistente que você resolveu recentemente.

Como você reage quando alguém é muito insistente com você?

A insistência é uma virtude ou um defeito? Explique.

Descreva uma paisagem com uma chuva insistente.

Frequently Asked Questions

10 questions

No, it is a uniform adjective. You say 'Ela é insistente' and 'Ele é insistente'. The ending '-e' remains the same for both genders.

While similar, 'insistente' usually implies a repetitive demand or action (like asking many times), whereas 'persistente' implies a long-term effort or a state that lasts a long time without giving up.

The adverbial form is 'insistentemente'. You add '-mente' to the adjective form.

It can be both. It is positive when it means 'persevering' (e.g., in studies) and negative when it means 'annoying' (e.g., a telemarketer).

Yes, 'chuva insistente' is a very common expression for rain that doesn't stop for a long time.

The 's' between the two 'i's is pronounced like a 'z' sound, as in 'zebra'.

The plural is 'insistentes'. You simply add an 's' at the end.

The noun is 'insistência', which means 'insistence'.

No, that is incorrect. You must say 'vendedora insistente' because the adjective does not change for gender.

Yes, it is a very common word used in daily conversation, news, and literature.