This page in your language

فارسی

العربية

Deutsch

Español

Français

日本語

한국어

Português

中文

हिन्दी

A2 adjective 6 min read

不高兴

bù gāoxìng

Practice it Examples Notes & Tips 不高兴 in 30 Seconds

Explanation 不高兴 in your Level:

At the A1 level, you learn '不高兴' as the direct opposite of '高兴' (happy). It is used in simple 'Subject + 很 + Adjective' sentences. You use it to tell people how you feel in a very basic way, like '我不高兴' (I am not happy). It's helpful for expressing basic needs or reactions to immediate events, like losing a toy or missing a bus. You don't need to worry about complex grammar; just treat it as a single unit meaning 'unhappy.'

At the A2 level, you start using '不高兴' with more adverbs like '有一点' (a little bit) or '非常' (very). You also learn the structure '让/叫 someone 不高兴' (to make someone unhappy). You can use it to describe other people's moods based on their facial expressions. You should also begin to notice the difference between '不高兴' and '生气' (angry). At this level, you might use '了' at the end to show that someone *became* unhappy because of something that happened.

At the B1 level, you use '不高兴' to describe more complex social situations. You understand that it can mean 'displeased' in a professional context. You can use it in conditional sentences like '如果你不高兴，我就不去' (If you're unhappy, I won't go). You also start to recognize it in common phrases and understand that it can sometimes imply a lack of willingness (e.g., 'he doesn't feel like doing it'). You use it to provide reasons for behaviors.

At the B2 level, you can distinguish '不高兴' from more nuanced synonyms like '郁闷' (gloomy) or '沮丧' (depressed). You understand its use in idiomatic expressions and literature. You can describe the 'why' behind the unhappiness using more complex conjunctions. You also understand the cultural nuance of 'saving face' and how '不高兴' might be used as a softer way to express deep dissatisfaction or even protest without being overtly rude.

At the C1 level, you recognize '不高兴' in diverse registers, from formal writing to colloquial slang. You can analyze how it is used in psychological descriptions in novels to show a character's internal state. You understand the historical and cultural background of the component characters '高' and '兴.' You can use the term in subtle ways, perhaps sarcastically or to describe a specific social atmosphere. You are comfortable using it in debates about emotional intelligence.

At the C2 level, '不高兴' is just one tool in a vast arsenal of emotional descriptors. You understand its most subtle implications in high-level diplomacy or classical literature. You can discuss the philosophical implications of 'happiness' (高兴) and its negation. You can use it to critique social norms regarding the expression of negative emotions in different historical periods of China. Your usage is indistinguishable from a native speaker in terms of timing and context.

Practice it Examples Notes & Tips

不高兴 in 30 Seconds

A versatile adjective meaning 'unhappy' or 'displeased.'
Used for moods, pouting, or reacting to minor disappointments.
Structurally used with '很' (hěn) as a linking adverb.
Less intense than '生气' (angry) and less tragic than '难过' (sad).

The Chinese word 不高兴 (bù gāoxìng) is one of the most common ways to express a negative emotional state. Literally translated, it means 'not happy' or 'not glad.' However, its usage in daily life is much broader than the English word 'unhappy.' It covers a spectrum of feelings ranging from mild disappointment and being 'miffed' to visible displeasure or even a sulky mood. In Chinese culture, where direct confrontation is often avoided, saying '我不高兴' (I am unhappy) is a relatively direct way to signal that something is wrong without necessarily using more intense words like '生气' (angry) or '难过' (sad/heartbroken).

Emotional Range: Covers everything from being slightly annoyed to being genuinely sad or dissatisfied with a situation.
Social Context: Often used by children when they don't get what they want, or by adults to express a grumpy mood (小情绪).

你为什么看起来有点不高兴？ (Why do you look a bit unhappy?)

因为下雨，孩子们都不高兴了。 (The children are unhappy because it is raining.)

Visual Cues: Often associated with pouting, a long face (拉着脸), or silence.

老板今天好像有点不高兴，你说话小心点。 (The boss seems a bit unhappy today; be careful with what you say.)

Frequency: Extremely high. It is one of the first 500 words a learner should master for emotional expression.

如果你不高兴，就告诉我。 (If you are unhappy, just tell me.)

他听到这个消息后非常不高兴。 (He was very unhappy after hearing this news.)

Using 不高兴 is structurally straightforward because it acts as a predicative adjective. In Chinese, you don't need the verb 'to be' (是) when using adjectives to describe a state. Instead, you usually use an adverb like '很' (hěn) to link the subject and the adjective. For example, 'I am unhappy' is '我很不高兴' (Wǒ hěn bù gāoxìng). If you omit the '很', the sentence often implies a comparison or sounds incomplete in spoken Chinese.

Structure 1: Subject + (Adverb of Degree) + 不高兴. Example: 他有一点不高兴 (He is a little bit unhappy).
Structure 2: Subject + 让/叫 + Person + 不高兴. Example: 这件事让他很不高兴 (This matter made him very unhappy).

你别不高兴了，我们去吃冰淇淋吧。 (Don't be unhappy anymore, let's go eat ice cream.)

我一说加班，大家都很不高兴。 (As soon as I mentioned overtime, everyone became very unhappy.)

Common Adverbs: 很 (hěn - very), 非常 (fēicháng - extremely), 有点 (yǒudiǎn - a bit), 太...了 (tài...le - too...).

看他的样子，好像真不高兴了。 (Looking at him, it seems he's really unhappy now.)

他表面上没事，其实心里很不高兴。 (On the surface he's fine, but in his heart he is very unhappy.)

没有什么好不高兴的。 (There is nothing to be unhappy about.)

You will hear 不高兴 in almost every social setting in China. In family life, parents use it to describe a child's tantrum or moodiness. In the workplace, it’s a safer, more professional way to describe morale issues than saying employees are 'angry' (生气). It also appears frequently in media, from TV dramas where characters describe their feelings to news reports about public dissatisfaction.

At Home: '宝宝不高兴了' (The baby is unhappy/pouting).
In Romance: '你是不是不高兴我昨天没打电话？' (Are you unhappy that I didn't call yesterday?).

大家对这个决定都很不高兴。 (Everyone is very unhappy with this decision.)

别让他不高兴，他可是我们的贵客。 (Don't make him unhappy; he is our VIP guest.)

Pop Culture: There is a famous Chinese animation character named '不高兴' (Mr. Unhappy) from the series '没头脑和不高兴'.

既然你不高兴，那我们就别去了。 (Since you are unhappy/don't want to, then let's not go.)

我今天不高兴干活。 (I'm not in the mood to work today.)

看到他不高兴，我也很难受。 (Seeing him unhappy makes me feel bad too.)

One of the most frequent errors English speakers make is using the verb '是' (shì) with 不高兴. In English, we say 'I *am* unhappy,' but in Chinese, adjectives include the 'to be' meaning within them. Saying '我是不高兴' (Wǒ shì bù gāoxìng) is grammatically incorrect unless you are emphasizing the fact ('I *really am* unhappy'). Another mistake is confusing '不高兴' with '难过' (nánguò). While both relate to negative feelings, '难过' is for deep sadness or feeling 'sorry,' whereas '不高兴' is for general displeasure or moodiness.

Mistake 1: Using '是': '我是不高兴' (Wrong) vs '我不高兴' (Right).
Mistake 2: Over-using '很': While '很' is a common linker, learners sometimes use it when they want to say 'very,' but forget that in Chinese it is often just a neutral grammatical requirement.

不要说：“我很难过”如果你只是因为没买到咖啡而生气。 (Don't say 'I'm very sad' if you're just annoyed about not getting coffee; use '不高兴'.)

他不高兴的样子很明显。 (His unhappy look is very obvious.)

Mistake 3: Using it for people only: While mainly for people, you can't say a 'situation' is '不高兴'. Use '令人不快' (lìng rén bù kuài) for situations.

这真是一个不高兴的消息。(Wrong) -> 这是一个让人不高兴的消息。(Right)

你为什么又不高兴了？ (Why are you unhappy again?)

请不要为了这点小事而不高兴。 (Please don't be unhappy over such a small thing.)

To sound more natural and precise in Chinese, you should learn when to use 不高兴 versus its synonyms. While it is the 'safe' choice, other words can express more specific nuances of negativity.

难过 (nánguò): Meaning 'sad' or 'feeling bad.' Use this when you feel emotional pain or grief. Example: 奶奶去世了，我很难过。
生气 (shēngqì): Meaning 'angry.' Use this when there is active rage or indignation. Example: 他骗了我，我很生气。
郁闷 (yùmèn): Meaning 'depressed' or 'gloomy.' Use this for a lingering, heavy feeling of being stuck or bored and unhappy. Example: 这几天下雨，不能出门，真郁闷。

如果你觉得受了委屈，你可能会感到不高兴。 (If you feel wronged, you might feel unhappy.)

他今天的情绪很低落，比不高兴更严重。 (His mood is very low today, which is more serious than just being unhappy.)

伤心 (shāngxīn): Heartbroken. Much stronger than '不高兴'. Usually involves crying.

我只是有点不高兴，没那么伤心。 (I'm just a bit unhappy, not that heartbroken.)

别在那儿不高兴了，快过来玩！ (Stop being unhappy over there, come over and play!)

他不说话就代表他不高兴。 (If he doesn't talk, it means he is unhappy.)

How Formal Is It?

Fun Fact

The character '兴' (xìng) in '高兴' originally referred to 'rising' or 'starting up,' implying that happiness is a state where your energy 'rises.'

Pronunciation Guide

UK /buː ɡaʊ ʃɪŋ/

US /bu ɡaʊ ʃɪŋ/

Stress is usually placed on the 'bu' for emphasis, or equally across 'gao-xing'.

Rhymes With

高兴 (gāoxìng) 助兴 (zhùxìng) 扫兴 (sǎoxìng) 尽兴 (jìnxìng) 败兴 (bàixìng) 乘兴 (chéngxìng) 雅兴 (yǎxìng) 即兴 (jíxìng)

Common Errors

Pronouncing 'xing' as a rising tone.
Forgetting the tone sandhi of 'bu' (it becomes 2nd tone bù -> bú when followed by a 4th tone, but here gāo is 1st tone, so bù remains 4th).
Over-emphasizing the 'xing' which can be neutral in some dialects.
Mispronouncing the 'g' in 'gao' as a soft 'j'.
Mixing up the vowels in 'gao' (ao) and 'xing' (ing).

Difficulty Rating

Reading 2/5

Characters are basic; '高' and '兴' are taught early.

Writing 3/5

The character '兴' (xìng) has several strokes and requires practice.

Speaking 2/5

Easy to pronounce; remember the tones.

Listening 1/5

Very distinct sound; easy to recognize in context.

What to Learn Next

Prerequisites

高兴高兴不很

Learn Next

生气难过担心害怕舒服

Advanced

郁闷沮丧愤慨凄凉惆怅

Grammar to Know

Adjectives as predicates

我不高兴。 (No 'is' needed).

Degree adverbs

我非常不高兴。 (Adds intensity).

Change of state '了'

他不高兴了。 (He wasn't, but now he is).

Causative '让'

这让我不高兴。 (A makes B feel C).

Tone sandhi of '不'

我不高兴 (bù gāoxìng) - remains 4th tone.

Examples by Level

我不高兴。

I am unhappy.

Simple Subject + Adjective.

他不高兴。

He is unhappy.

Simple Subject + Adjective.

妈妈不高兴。

Mom is unhappy.

Simple Subject + Adjective.

老师不高兴。

The teacher is unhappy.

Simple Subject + Adjective.

你为什么不高兴？

Why are you unhappy?

Question with '为什么'.

我很不高兴。

I am very unhappy.

Use of '很' as a linker.

他不高兴了。

He became unhappy.

Use of '了' for change of state.

你不高兴吗？

Are you unhappy?

Question with '吗'.

他有一点不高兴。

He is a little bit unhappy.

Adverb '有一点'.

这件事让他不高兴。

This matter made him unhappy.

Causative '让'.

看到你，他就不高兴。

He is unhappy as soon as he sees you.

Structure '一...就...' implied.

别不高兴了，笑一个。

Don't be unhappy anymore, give us a smile.

Imperative '别...了'.

他今天看起来很不高兴。

He looks very unhappy today.

Verb '看起来'.

因为没买到书，她不高兴。

She is unhappy because she didn't buy the book.

Conjunction '因为'.

谁让你不高兴了？

Who made you unhappy?

Question with '谁' and '让'.

我不高兴去那里。

I don't feel like going there.

Usage meaning 'not in the mood'.

如果你不高兴，我们就回家。

If you are unhappy, we will go home.

Conditional '如果...就...'.

他为了这点小事就不高兴，太小气了。

He is unhappy over such a small thing; he's too petty.

Structure '为了...就...'.

大家对新的规则都很不高兴。

Everyone is very unhappy with the new rules.

Preposition '对'.

他表面上笑着，心里却很不高兴。

He is smiling on the surface, but he is very unhappy in his heart.

Contrast with '表面上...却...'.

没必要为了他而不高兴。

There's no need to be unhappy because of him.

Structure '没必要...而...'.

他听到这话，脸上立刻露出了不高兴的神情。

Hearing this, an unhappy expression immediately appeared on his face.

Noun phrase '不高兴的神情'.

他总是无缘无故地不高兴。

He is always unhappy for no reason.

Adverb '无缘无故地'.

只要你不高兴，我都会陪着你。

As long as you are unhappy, I will stay with you.

Conjunction '只要'.

他的沉默其实就是一种不高兴的表现。

His silence is actually a manifestation of unhappiness.

Noun '表现'.

尽管他不高兴，但他还是参加了会议。

Even though he was unhappy, he still attended the meeting.

Conjunction '尽管...还是...'.

这种不高兴的情绪在办公室里蔓延。

This unhappy mood spread throughout the office.

Verb '蔓延'.

他那副不高兴的样子，谁见了都害怕。

Everyone is afraid when they see that unhappy look of his.

Structure '...谁...都...'.

别把不高兴带回家里。

Don't bring your unhappiness home.

'把' structure.

他并没有表现出任何不高兴。

He didn't show any unhappiness at all.

Negation '并没有'.

你这样说话，难免会让人不高兴。

Speaking like this, it's unavoidable that people will be unhappy.

Adverb '难免'.

我不高兴的是你竟然骗我。

What I'm unhappy about is that you actually lied to me.

Emphasis '...的是...'.

他那种隐忍的不高兴，比爆发出来的愤怒更可怕。

His restrained unhappiness is scarier than an outburst of anger.

Adjective '隐忍的'.

这种不高兴源于他对自己现状的不满。

This unhappiness stems from his dissatisfaction with his current situation.

Verb '源于'.

他甚至都不屑于掩饰他的不高兴。

He didn't even deign to hide his unhappiness.

Structure '不屑于'.

哪怕只有一点点不高兴，她也会察觉到。

Even if there's only a tiny bit of unhappiness, she will notice it.

Conjunction '哪怕'.

这种不高兴的情绪，在很大程度上影响了他的判断力。

This unhappy mood, to a large extent, affected his judgment.

Phrase '在很大程度上'.

他试图通过运动来排解心中的不高兴。

He tried to resolve the unhappiness in his heart through exercise.

Verb '排解'.

他的言辞中充满了不高兴的意味。

His words were full of an unhappy tone.

Noun '意味'.

不要让暂时的不高兴阴蔽了你对未来的希望。

Don't let temporary unhappiness cloud your hope for the future.

Metaphorical use.

这种集体性的不高兴，是社会转型期的阵痛。

This collective unhappiness is the labor pain of a social transition period.

Sociological context.

他将个人的不高兴升华为一种对人类命运的忧思。

He sublimated his personal unhappiness into a concern for the fate of humanity.

Verb '升华'.

在那个时代，连表达不高兴都是一种奢侈。

In that era, even expressing unhappiness was a luxury.

Historical nuance.

这种不高兴并非无本之木，而是有着深层的历史根源。

This unhappiness is not without foundation; it has deep historical roots.

Idiom '无本之木'.

他以一种近乎冷酷的理智来审视自己的不高兴。

He examines his own unhappiness with an almost cold rationality.

Complex adverbial phrase.

这种不高兴在潜意识中影响着他的每一个决策。

This unhappiness affects his every decision in his subconscious.

Term '潜意识'.

他那不高兴的性格，注定了他一生的坎坷。

His unhappy disposition doomed him to a life of hardships.

Verb '注定'.

我们应当学会与自己的不高兴共处，而非一味地逃避。

We should learn to coexist with our unhappiness rather than blindly escaping it.

Philosophical advice.

Common Collocations

有点不高兴

非常不高兴

看起来不高兴

让...不高兴

心里不高兴

满脸不高兴

表现出不高兴

莫名其妙地不高兴

为了...而不高兴

不高兴的神情

Common Phrases

不高兴了

— Became unhappy or started pouting.

宝宝不高兴了。

有什么不高兴的？

— What is there to be unhappy about?

大家都赢了，你有什么不高兴的？

别不高兴

— Don't be unhappy; cheer up.

别不高兴了，我请你吃饭。

一脸不高兴

— A face full of unhappiness.

他一脸不高兴地坐在那儿。

心里很不高兴

— Very unhappy deep down.

虽然他没说，但我知道他心里很不高兴。

真不高兴

— Really unhappy/What a bummer.

今天又要加班，真不高兴。

有点儿不高兴

— A little bit unhappy.

他听到这个消息，有点儿不高兴。

谁不高兴？

— Who is unhappy?

我看谁不高兴了？

让他不高兴

— To make him unhappy.

我不想让他不高兴。

没理由不高兴

— No reason to be unhappy.

你都拿第一了，没理由不高兴。

Often Confused With

不高兴 vs 难过 (nánguò)

难过 is for deep sadness/grief; 不高兴 is for displeasure/moodiness.

不高兴 vs 生气 (shēngqì)

生气 is active anger; 不高兴 can be passive pouting.

不高兴 vs 不舒服 (bù shūfu)

不舒服 is physical discomfort; 不高兴 is emotional.

Idioms & Expressions

"没头脑和不高兴"

— A famous cartoon pair; one is scatterbrained and the other is always grumpy.

他们俩真是没头脑和不高兴。

Colloquial

"闷闷不乐"

— Depressed; moody; in low spirits.

他最近总是闷闷不乐的。

Idiomatic

"郁郁寡欢"

— Very unhappy and quiet.

自从失业后，他一直郁郁寡欢。

Literary

"愁眉苦脸"

— To wear a distressed expression; a long face.

别整天愁眉苦脸的，事情总会解决。

Colloquial

"怏怏不乐"

— Discontented and unhappy.

他怏怏不乐地离开了会场。

Formal

"愤愤不平"

— Be indignant; feel aggrieved and unhappy about an injustice.

对于这个结果，大家都感到愤愤不平。

Neutral

"闷声不响"

— To keep quiet due to being unhappy or moody.

他不高兴的时候就闷声不响。

Colloquial

"拉长了脸"

— To pull a long face (showing unhappiness).

一说要写作业，他就拉长了脸。

Colloquial

"满腹牢骚"

— Full of grievances and unhappiness.

他最近满腹牢骚，见谁都抱怨。

Neutral

"垂头丧气"

— Dejected; crestfallen.

考试没考好，他垂头丧气地回了家。

Neutral

Easily Confused

不高兴 vs 难受

Both involve feeling 'bad.'

难受 is internal discomfort (emotional or physical); 不高兴 is specifically about being unhappy/displeased.

心里很难受 vs. 脸上的不高兴。

不高兴 vs 伤心

Both relate to sadness.

伤心 is 'heartbroken' and much more intense.

丢了钱不高兴 vs. 宠物死了很伤心。

不高兴 vs 扫兴

Both relate to negative mood.

扫兴 is specifically when fun is interrupted.

下雨很扫兴。

不高兴 vs 不满

Both relate to dissatisfaction.

不满 is more formal and specific to a grievance.

对结果不满。

不高兴 vs 郁闷

Both relate to bad moods.

郁闷 is 'depressed/bored/stuck.'

没法出门真郁闷。

Sentence Patterns

S + 不高兴

我不高兴。

S + 很 + 不高兴

他很不高兴。

S + 有点(儿) + 不高兴

她有点儿不高兴。

让 + S + 不高兴

别让他不高兴。

如果...就 + 不高兴

如果你不去，他就不高兴。

S + 看起来 + 不高兴

你看起来不高兴。

S + 表面上...心里 + 不高兴

他表面上没事，心里很不高兴。

S + 满脸 + 不高兴

他满脸不高兴地进来了。

Word Family

Nouns

不快 (bùkuài)

情绪 (qíngxù)

Verbs

生气 (shēngqì)

发愁 (fāchóu)

Adjectives

高兴 (gāoxìng)

扫兴 (sǎoxìng)

难过

伤心

痛苦

烦恼

忧虑

How to Use It

frequency

Extremely common in spoken Mandarin across all age groups.

Common Mistakes

我是不高兴 → 我不高兴
Chinese adjectives function like verbs and don't need the copula 'shì'.
他很伤心 (when they mean unhappy) → 他不高兴
伤心 is for deep grief; don't use it for minor displeasure.
这件事是不高兴的 → 这件事让人不高兴
Situations 'make people' unhappy; they aren't 'unhappy' themselves.
我不高兴和你去 → 我不想和你去 / 我不高兴去
Be careful; '不高兴' as 'don't feel like' is colloquial and needs specific phrasing.
他有一点难过 (for a small annoyance) → 他有一点不高兴
难过 is too heavy for small annoyances.

Tips

Avoid 'Shì'

Never say 'Wǒ shì bù gāoxìng' to mean 'I am unhappy.' Just say 'Wǒ bù gāoxìng.'

The 'Pout' Factor

In Chinese, '不高兴' is often the word used for children pouting. Adults use it too, but it can sound slightly childish.

Degree Matters

Use '有一点' (a little) to soften the blow if you're telling someone you're unhappy with them.

Listen for 'Le'

If you hear 'bù gāoxìng le,' something just changed. It means the person *became* unhappy.

Tone Sandhi

Remember 'bù' stays 4th tone because 'gāo' is 1st tone.

Character 'Xing'

The top of '兴' has three points. Practice the stroke order carefully.

Softening Dissatisfaction

Saying '我有点不高兴' is a polite way to let a friend know they crossed a line.

Mood vs. Emotion

Use it for a temporary mood. For a long-term state, '不快乐' (not happy in life) is better.

Cartoon Reference

Referencing '没头脑和不高兴' is a fun way to tease a grumpy friend.

Causative Usage

Master the 'Ràng someone bù gāoxìng' structure; it's very useful for explaining social friction.

Memorize It

Mnemonic

Think of 'Bu' as 'Boo!' (unhappy sound) and 'Gao' as 'Gao' (high). You are 'Boo-ing' the 'High' spirits. No high spirits = Unhappy.

Visual Association

Imagine a balloon (high spirit) that has been popped (Bu). The deflated balloon represents '不高兴'.

Word Web

高兴不高兴很难过很生气有一点不高兴不高兴了非常不高兴真不高兴

Challenge

Try to use '不高兴' in three different ways today: once for yourself, once for a friend, and once for a character in a movie.

Word Origin

The word is a modern compound. '不' (bù) is an ancient negation particle. '高兴' (gāoxìng) literally means 'high spirit.'

Original meaning: The negation of having a high spirit or being in a state of joy.

Sino-Tibetan (Sinitic).

Cultural Context

Be careful using it with superiors; it can sound childish or disrespectful if not phrased correctly (e.g., use '对...感到不快' in formal settings).

English speakers might find '不高兴' more versatile than just 'unhappy.' It often translates better as 'displeased' or 'not in the mood.'

The cartoon '没头脑和不高兴' (Mr. Scatterbrain and Mr. Unhappy). Commonly used in Mandopop songs to describe romantic pouting. Frequent in Weibo 'mood' posts.

Practice in Real Life

Real-World Contexts

Losing a game

输了不高兴
真不高兴
别不高兴
下次会赢

Bad weather

天气不好，不高兴
真扫兴
没法出去玩
不高兴出门

Work stress

加班不高兴
老板不高兴
压力大
心情不好

Relationship issues

他又不高兴了
哄他不高兴
别生我不高兴的气
为什么不高兴？

Childhood/Parenting

孩子不高兴
别哭，别不高兴
买个玩具就不高兴了
宝宝不高兴

Conversation Starters

"你今天看起来有点不高兴，发生什么事了？"

"如果你不高兴，一定要告诉我，好吗？"

"为什么他听到这个消息会这么不高兴？"

"别为了这种小事不高兴，不值得。"

"你是不高兴我没等你吗？"

Journal Prompts

写一件让你感到不高兴的小事，并说明原因。

当你感到不高兴的时候，你会做什么来让自己开心起来？

描述一次你让别人不高兴的经历，你后来是怎么做的？

你觉得不高兴是一种负面的情绪吗？为什么？

如果你的好朋友不高兴，你会怎么安慰他？

Frequently Asked Questions

10 questions

Usually no. Use '我不高兴' or '我很不高兴.' Adjectives in Chinese don't need 'is' (是) unless you are emphasizing a fact.

不高兴 is 'unhappy/displeased' (like pouting). 难过 is 'sad/feeling bad' (like after a breakup).

Use '非常不高兴' (fēicháng bù gāoxìng) or '很不高兴' (hěn bù gāoxìng).

It's neutral. With elders, it's better to be more descriptive or polite, but it's not inherently rude.

Yes, in some contexts like '我不高兴去,' it means 'I'm not in the mood to go' or 'I don't feel like going.'

Yes, it is 4th tone (xìng). In some fast speech, it might sound neutral, but learn it as 4th.

You can say '别不高兴了' (Don't be unhappy anymore) or '哄他开心' (Coax him to be happy).

Not directly. Instead of 'This situation is unhappy,' say '这件事让人不高兴' (This matter makes people unhappy).

It can, but it's a 'softer' anger. It's more about being displeased than being full of rage.

The direct opposite is '高兴' (happy/glad).