Primer Condicional: When vs If (Probabilidad y Momento)
posibilidad) de 'when' (cuando es una certeza).
Grammar Rule in 30 Seconds
Use 'If' for things that might happen and 'When' for things that definitely will happen in the future.
- Use 'If' for possibilities: 'If it rains, I'll stay home.' (Maybe it rains).
- Use 'When' for certainties: 'When I get home, I'll call you.' (I will definitely get home).
- Never use 'will' immediately after 'if' or 'when' in the condition clause.
Overview
First Conditional es una de las estructuras más fundamentales y útiles en el idioma inglés, especialmente cuando queremos hablar de planes, posibilidades y consecuencias lógicas en el futuro. Si alguna vez has querido decir en inglés algo como si tengo tiempo, te llamoo
cuando llegue a casa, cenaremos, entonces ya estás pensando en el primer condicional. Esta estructura nos permite conectar una condición real con un resultado probable.
First Conditional suele ser bastante intuitivo porque la lógica de causa y efecto es muy similar a la que usamos en español. Sin embargo, hay matices importantes, especialmente en el uso de las palabras if (si) y when (cuando), que pueden cambiar completamente el sentido de lo que queremos expresar. Mientras que if introduce una posibilidad que puede o no ocurrir, when se refiere a algo que estamos seguros de que sucederá, enfocándose más en el momento en que esto pasará.if y la certeza de when.First Conditional se utiliza para hablar de situaciones que consideramos reales y posibles. A diferencia de otros condicionales que exploran mundos imaginarios o imposibles, el primer condicional tiene los pies en la tierra. Se compone de dos partes o cláusulas: la cláusula de la condición (introducida por if o when) y la cláusula del resultado.Si estudias, apruebas. O incluso usamos el futuro en la segunda parte:
Si estudias, aprobarás.
- 1La cláusula de la condición (la que lleva
ifowhen) siempre va en Present Simple. - 2La cláusula del resultado suele ir en Future Simple (con
will).
if o el when ya están marcando que estamos hablando de una condición futura. En inglés, se considera redundante poner will en la misma frase que el condicional.Present Simple actúa aquí como un marcador de tiempo futuro. Es como si el
if absorbiera la energía del futuro, dejando al verbo en su forma más simple.If(Si): Lo usamos cuando no estamos seguros de que la condición se cumpla. Hay un 50% de probabilidad de que ocurra y un 50% de que no. Es una contingencia.- Ejemplo:
If I have money, I will buy the tickets.(Quizás tenga el dinero, quizás no). When(Cuando): Lo usamos cuando estamos seguros de que el evento ocurrirá. La duda no es elsi, sino elcuándo.- Ejemplo:
When I get home, I will call you.(Es seguro que llegaré a casa, solo es cuestión de tiempo).
si para todo. En inglés, ser preciso con when demuestra un nivel de confianza y claridad mucho mayor en tu discurso.First Conditional es como una fórmula matemática que siempre debes seguir para no cometer errores. Aquí te presento el patrón estándar:if / when) | Coma | Cláusula de Resultado (Futuro) |If / When + Sujeto + Present Simple | , | Sujeto + will + Verbo en infinitivo |If I see him, | , | I will tell him. |When the movie ends, | , | we will go to dinner. |- 1El orden de los factores no altera el producto: Puedes poner la cláusula de resultado al principio. En ese caso, no se usa la coma.
I will tell him if I see him.We will go to dinner when the movie ends.
- 1El uso de
will: Recuerda quewillnunca, bajo ninguna circunstancia (en este nivel), va inmediatamente después deifowhen. Es el error más común de los hispanohablantes porque en español a veces pensamos: «Si yo *iré*...». ¡Ojo con esto! - 2Variaciones del resultado: Aunque
willes lo más común, también puedes usar otros verbos modales comocan,may,mightoshouldpara cambiar el matiz de la consecuencia.
If you finish early, you can leave.(Permiso/Habilidad)If it rains, we might stay at home.(Posibilidad débil)
If she arrives late... | Si ella llega tarde... (Presente Indicativo) |When she arrives late... | Cuando ella llegue tarde... (Subjuntivo) |cuando para el futuro, saltamos automáticamente al subjuntivo (llegue). En inglés, el subjuntivo casi no existe en estos casos, así que simplemente usamos el Present Simple (arrives). Esto simplifica mucho las cosas una vez que te acostumbras.First Conditional es extremadamente versátil. Aquí te detallo las situaciones más comunes donde lo aplicarás, diferenciando siempre entre la incertidumbre de if y la certeza de when.If para alternativas)If the flight is on time, I'll be at the hotel by 8 PM.(El vuelo podría retrasarse, es una posibilidad).If we get the contract, we will celebrate on Friday.(Aún no sabemos si nos darán el contrato).
When para certezas)When I finish this meeting, I'll send you the report.(Voy a terminar la reunión, es seguro).When the sun goes down, it will get colder.(El sol se va a poner, no hay duda).
if.If you don't wear a coat, you'll get sick.(Advertencia).If you are late again, the boss will be furious.(Consecuencia negativa).
If you help me with this, I'll buy you lunch.(Promesa condicionada).When you sign the document, we will release the payment.(Aquí usamoswhenpara indicar que esperamos que la firma ocurra pronto y con seguridad).
when es tu mejor aliado para marcar la transición entre pasos.When the water boils, add the pasta.(Primero hierve el agua, luego la pasta).When you arrive at the station, call me.(Primero llegas, luego llamas).
Will en la condiciónIf I will go to the party, I will see her.- ¿Por qué ocurre? En español a veces usamos estructuras que suenan a futuro en ambas partes, o simplemente queremos enfatizar que todo el evento es futuro.
- La corrección: Elimina el primer
will. Lo correcto es:If I go to the party, I will see her.
If con When en situaciones de incertidumbreWhen I win the lottery, we will travel the world.- El problema: Al usar
when, estás diciendo que es seguro que vas a ganar la lotería. A menos que tengas el futuro comprado, esto suena muy extraño o demasiado arrogante en inglés. - La corrección: Usa
ifpara cosas que son poco probables o que no controlas:If I win the lottery....
S de la tercera personaPresent Simple, ¡no olvides las reglas del presente!- Incorrecto:
If she call me, I will answer. - Correcto:
If she calls me, I will answer. - ¿Por qué ocurre? Estamos tan concentrados en la estructura del condicional que olvidamos la regla básica del presente simple para
he, she, it.
When con el subjuntivo mentalCuando *tenga* tiempo. Ese tenga es subjuntivo. Muchos estudiantes intentan buscar una forma especial del verbo en inglés para traducir ese sentimiento.- La corrección: No busques más, usa el presente normal.
When I have time. No esWhen I may haveniWhen I would have. Simple es mejor.
First Conditional con el Zero Conditional o el Second Conditional. Aquí tienes una tabla comparativa para que veas las diferencias de significado y estructura.If/When + Presente -> Presente | If you heat ice, it melts. |If/When + Presente -> Will + Infinitivo | If it's sunny, we will go to the beach. |If + Pasado Simple -> Would + Infinitivo | If I were a bird, I would fly. |Zero: Si llueve, la calle se moja. (Siempre pasa, es un hecho físico). ->If it rains, the street gets wet.First: Si llueve hoy, no iré al cine. (Es una situación específica hoy, no una ley universal). ->If it rains, I won't go to the cinema.
First: Si tengo dinero, compraré un coche. (Es posible, estoy ahorrando). ->If I have money, I will buy a car.Second: Si tuviera un millón de dólares, compraría una isla. (Es una fantasía, no tengo el dinero). ->If I had a million dollars, I would buy an island.
going to en lugar de will en el primer condicional?going to si el resultado es un plan que ya tenías en mente o si hay una evidencia clara.- Ejemplo:
If I fail this exam, my parents are going to be very angry.(Es una intención o una consecuencia segura basada en lo que conoces de tus padres).
unless?Unless significa a menos que o si no. Es como un if + not. Es muy común en el primer condicional.- Ejemplo:
I will go to the party unless it rains.(Es lo mismo que decir:I will go to the party if it doesn't rain).
when para hablar de algo que pasó en el pasado?First Conditional. El primer condicional es exclusivamente para mirar hacia el futuro. Si dices When I was a child, I played football, estás simplemente narrando el pasado en pasado simple.If o When. Si la palabra de unión está en el medio, la coma desaparece. Es una regla de puntuación que ayuda a la legibilidad, pero en el lenguaje hablado se traduce como una pequeña pausa.if es para la duda y when es para la cita segura en el calendario, habrás dado un paso gigante hacia la fluidez. ¡Mucho éxito en tu práctica!First Conditional Structure
| Clause Type | Conjunction | Subject | Verb Form | Example |
|---|---|---|---|---|
|
Condition
|
If / When
|
I / You / We / They
|
Present Simple (Base)
|
If they arrive...
|
|
Condition
|
If / When
|
He / She / It
|
Present Simple (+s/es)
|
When she arrives...
|
|
Result
|
(None)
|
Any Subject
|
Will + Base Verb
|
...we will start.
|
|
Negative Condition
|
If
|
Any Subject
|
Don't / Doesn't + Base
|
If it doesn't rain...
|
|
Negative Result
|
(None)
|
Any Subject
|
Won't + Base Verb
|
...we won't go.
|
Common Contractions
| Full Form | Contraction | Usage |
|---|---|---|
|
I will
|
I'll
|
Very common in speech
|
|
You will
|
You'll
|
Very common in speech
|
|
He will / She will
|
He'll / She'll
|
Very common in speech
|
|
It will
|
It'll
|
Common, but harder to hear
|
|
Will not
|
Won't
|
Standard negative
|
Meanings
The first conditional describes a real possibility in the future. 'If' introduces a condition that may or may not happen, while 'When' introduces an event the speaker is certain will occur.
Probability (If)
Used when the outcome depends on an uncertain event.
“If you study hard, you will pass the exam.”
“If we leave now, we'll catch the train.”
Certainty/Timing (When)
Used when the event is guaranteed to happen, and we are just waiting for the time to arrive.
“When the sun goes down, it will get cold.”
“When I turn 21, I'll have a big party.”
Immediate Sequence (As soon as)
A stronger version of 'when' emphasizing that the result happens immediately after the condition.
“As soon as the plane lands, I'll text you.”
“I'll pay the bill as soon as I get my salary.”
Reference Table
| Palabra clave | Probabilidad | Significado | Frase condicional | Frase principal |
|---|---|---|---|---|
|
If
|
Posible (50/50)
|
La condición podría ocurrir
|
If it rains tomorrow,
|
I'll stay home.
|
|
When
|
Cierto (100%)
|
El evento definitivamente ocurrirá
|
When I get home,
|
I'll eat dinner.
|
|
If
|
Baja probabilidad
|
Resultado condicional
|
If she wins the lottery,
|
she'll quit her job.
|
|
When
|
Momento esperado
|
Acción en ese punto
|
When the clock strikes five,
|
the meeting will end.
|
|
If
|
Advertencia/Consejo
|
Consecuencia de la condición
|
If you don't study,
|
you won't pass.
|
|
When
|
Evento predecible
|
Resultado de la certeza
|
When the baby cries,
|
I'll feed her.
|
|
Unless
|
Condición negativa
|
Si no...
|
Unless you hurry,
|
you'll be late.
|
Espectro de formalidad
Upon your arrival, would you be so kind as to contact me? (Communication)
When you arrive, please give me a call. (Communication)
Call me when you get there. (Communication)
Hit me up when you're there. (Communication)
Primer Condicional: If vs When
If (Posibilidad)
- Condición (puede o no ocurrir) If + Present Simple
- Resultado (consecuencia probable) will + Base Verb
When (Certeza)
- Evento (definitivamente ocurre) When + Present Simple
- Resultado (acción en ese momento) will + Base Verb
Error Común
- No 'will' después de if/when e.g., *If it rains*, not *If it will rain*
If vs When en el Primer Condicional
Eligiendo If o When
¿Estás hablando de un evento futuro?
¿Es el evento futuro *seguro* que ocurrirá?
¿Es el evento futuro *posible* pero no seguro?
Cuándo usar 'If' vs 'When'
Usa 'If' para...
- • Posibilidades
- • Condiciones
- • Planes de Contingencia
- • Advertencias/Consejos
Usa 'When' para...
- • Eventos Ciertos
- • Momento Esperado
- • Acciones Programadas
- • Secuencia de Eventos
¡Atención a...
- • No 'will' después de If/When
- • Coma después de la frase inicial
- • Claridad de significado
Ejemplos por nivel
If it is cold, I will wear a coat.
If it is cold, I will wear a coat.
When I go home, I will sleep.
When I go home, I will sleep.
If you are hungry, we will eat.
If you are hungry, we will eat.
When the bus comes, we will get on.
When the bus comes, we will get on.
If I have time, I'll call you later.
If I have time, I'll call you later.
When the movie starts, please be quiet.
When the movie starts, please be quiet.
If she doesn't arrive soon, we'll leave.
If she doesn't arrive soon, we'll leave.
I'll buy a new phone when I have enough money.
I'll buy a new phone when I have enough money.
If the weather stays like this, the crops will fail.
If the weather stays like this, the crops will fail.
When you finish the report, will you send it to me?
When you finish the report, will you send it to me?
If we don't reduce costs, we won't make a profit.
If we don't reduce costs, we won't make a profit.
As soon as I hear any news, I'll let you know.
As soon as I hear any news, I'll let you know.
If the interest rates rise, the housing market will likely cool down.
If the interest rates rise, the housing market will likely cool down.
When the results are published, we'll be able to see the impact.
When the results are published, we'll be able to see the impact.
If you happen to see Mark, will you tell him I'm looking for him?
If you happen to see Mark, will you tell him I'm looking for him?
Unless they provide more funding, the project will be cancelled.
Unless they provide more funding, the project will be cancelled.
Should the negotiations fail, the company will face bankruptcy.
Should the negotiations fail, the company will face bankruptcy.
If you will just sign here, we'll finalize the paperwork.
If you will just sign here, we'll finalize the paperwork.
When the dust finally settles, we'll see who was right.
When the dust finally settles, we'll see who was right.
If it weren't for the rain, we'd be having a great time (Mixed/First overlap).
If it weren't for the rain, we'd be having a great time.
If the minister is to resign, it will happen before the weekend.
If the minister is to resign, it will happen before the weekend.
Whensoever the opportunity arises, I shall take it.
Whensoever the opportunity arises, I shall take it.
If you would be so kind as to wait, the doctor will be with you shortly.
If you would be so kind as to wait, the doctor will be with you shortly.
Provided that the conditions are met, the merger will proceed as planned.
Provided that the conditions are met, the merger will proceed as planned.
Fácil de confundir
Both use 'if' and present tense. Learners don't know when to use 'will'.
Learners use the First Conditional for impossible things.
Learners want to use 'will' after any time word.
Errores comunes
If it will rain, I stay.
If it rains, I'll stay.
When I will see him...
When I see him...
If he go, I will go.
If he goes, I will go.
I will call you if I will arrive.
I will call you when I arrive.
If I see him I will tell him.
If I see him, I will tell him.
If it rains, I stay home.
If it rains, I will stay home.
When I'll finish, I'll call.
When I finish, I'll call.
If I would see him, I will tell him.
If I see him, I will tell him.
Unless it doesn't rain, we'll go.
Unless it rains, we'll go.
When I win the lottery, I'll buy a car.
If I win the lottery, I'll buy a car.
Patrones de oraciones
If I ___, I will ___.
When I ___, I'll ___.
I won't ___ unless ___.
As soon as ___, we will ___.
Real World Usage
If you're free later, let's grab a coffee.
If I am selected for this role, I will work hard to exceed expectations.
When the gate opens, we'll board the plane.
If you spend over $50, you'll get free shipping.
When the water boils, add the pasta.
If the storm continues, flights will be delayed.
Piensa: '¿Qué tan probable es?'
¡Ni se te ocurra poner 'will' después de 'if' o 'when'!
Usa la coma si la condición va primero
, pero I'll say hi when I see her."¡El contexto lo es todo!
If you want to sound professional, use them right.
Smart Tips
Bite your tongue! Replace 'will' with the simple present tense immediately.
Ask yourself: 'Is there any chance this won't happen?' If yes, use 'if'.
Swap 'when' for 'as soon as'. It adds a sense of priority to your plans.
Use 'Provided that' instead of 'If' to sound more professional and precise.
Pronunciación
Contraction Stress
In the result clause, 'I'll' or 'you'll' are usually unstressed. The stress falls on the main verb.
The 'If' Rise
When the 'if' clause comes first, the voice usually rises at the comma to show the sentence isn't finished.
Conditional Rise-Fall
If you go ↗, I'll go ↘.
Standard conditional statement
Memorízalo
Mnemotecnia
If is a 'Maybe', When is a 'Date'. Both use the Present, so don't be late!
Asociación visual
Imagine a fork in the road for 'If' (two possible paths). Imagine a straight train track for 'When' (the train will definitely reach the station, it's just a matter of time).
Rhyme
After 'if' or 'when', the 'will' is a sin; use the simple present to let the meaning in.
Story
A traveler is planning a trip. He says, 'When I arrive in London, I'll see the Big Ben.' (Certainty). Then he says, 'If I have enough money, I'll buy a souvenir.' (Uncertainty). He never says 'will' until he's out of the 'if/when' zone.
Word Web
Desafío
Write down 3 things you will definitely do tonight (using 'When') and 3 things you might do if you have time (using 'If').
Notas culturales
British speakers often use 'should' in the if-clause to sound more polite or to suggest a lower probability.
Americans are very likely to use 'as soon as' in place of 'when' to emphasize promptness in business contexts.
Using 'When' instead of 'If' in negotiations can be a power move to show you assume the deal will happen.
Conditionals in English evolved from Old English 'gif' (if) and 'hwanne' (when).
Inicios de conversación
What will you do if it rains this weekend?
When you finish your English course, how will you use your skills?
If you win a million dollars tomorrow, what's the first thing you'll buy?
What will happen to the environment if we don't change our habits?
Temas para diario
Errores comunes
Test Yourself
___ it rains tomorrow, we'll stay inside.
Choose the correct sentence:
Find and fix the mistake:
When my boss will call, I'll tell her about the new client.
Translate into English: 'Si me envías un mensaje, te responderé.'
Answer starts with: ["I...
Score: /4
Ejercicios de practica
8 exercises___ I see him tomorrow, I'll give him your message. (It's possible I will see him, but not certain).
If she ___ (not/study), she will fail the exam.
Find and fix the mistake:
When I will get home, I will make dinner.
If it doesn't rain, we will have a picnic.
A: Are you coming to the party? B: I'm not sure. I'll come ___ I finish my work early.
Select the First Conditional sentence.
1. If you eat too much... 2. When the sun sets... 3. Unless you hurry...
You can use 'will' in both the 'if' clause and the 'result' clause.
Score: /8
Practice Bank
12 exercisesI'll make some coffee ___ you wake up.
If you will study, you will pass the exam.
Choose the correct sentence:
Translate into English: 'Cuando termine el trabajo, te llamaré.'
Arrange these words into a sentence:
Match the situations with the correct word:
Don't worry, I'll text you ___ I'm on my way.
If I will go to London, I'll visit the British Museum.
Choose the correct sentence:
Translate into English: 'Si hace sol, iremos de picnic.'
Arrange these words into a sentence:
Match the event type with the correct word:
Score: /12
Preguntas frecuentes (8)
Yes! You can use other modal verbs in the result clause to change the meaning. `If it's sunny, we can go to the beach` (ability/permission) or `If it's sunny, we might go` (lower certainty).
In 99% of cases at B1 level, yes. However, in very formal English, 'will' can be used after 'if' to mean 'if you are willing to' (e.g., `If you will just wait here...`).
`When` is general timing. `As soon as` is immediate. `When I get home, I'll eat` vs. `As soon as I get home, I'll eat` (the second one implies you are very hungry!).
Only if the `if` or `when` clause comes first. If it's in the middle, no comma is needed. `If it rains, I'll stay.` vs `I'll stay if it rains.`
No. The First Conditional is strictly for future possibilities. For the past, you would use the Third Conditional.
That is the Zero Conditional. It means 'Every time I see him, I tell him' (a habit). The First Conditional `I'll tell him` refers to one specific time in the future.
It is neutral. It's used in both conversation and writing. It's often easier than saying 'if... not'.
If the condition is impossible or very unlikely (like winning the lottery for most people), we often switch to the Second Conditional (`If I won...`). But if you just bought a ticket, the First Conditional is fine!
Scaffolded Practice
1
2
3
4
Mastery Progress
Needs Practice
Improving
Strong
Mastered
In Other Languages
Si + Presente / Cuando + Subjuntivo
English uses Present Simple for both 'if' and 'when', while Spanish changes the mood for 'when'.
Si + Présent / Quand + Futur
French uses the future tense after 'when', English does not.
Wenn + Präsens
German uses one word (wenn) for both possibilities and certainties.
〜たら (~tara) / 〜とき (~toki)
Japanese relies on conditional particles rather than a 'will' vs 'present' tense split.
إذا (Idha) / عندما (Indama)
Arabic often uses the past tense form to express the condition clause.
如果 (Rúguǒ) / 当...的时候 (Dāng... de shíhòu)
Chinese uses particles and word order instead of tense changes.
Learning Path
Prerequisites
Learn These First
Primer Condicional: Posibilidades Reales Futuras
### Overview El **First Conditional** (primer condicional) es una de las estructuras más potentes y utilizadas en el id...
Condicional Cero: Verdades Generales (If vs. When)
Overview ¿Alguna vez te has preguntado por qué tu profesor de inglés se emociona tanto con `if` y `when`? Es porque son...
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