一定
yī dìng HSK 3

English Meaning

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📚 Example Sentences

我一定去。
Wǒ yīdìng qù.
I will definitely go.
他一定在家。
Tā yīdìng zài jiā.
He is certainly at home.
明天一定下雨。
Míngtiān yīdìng xiàyǔ.
It will definitely rain tomorrow.
我一定来。
Wǒ yīdìng lái.
I will definitely come.
他一定知道。
Tā yīdìng zhīdào.
He certainly knows.

💡 Memory Tip

Think of 一 (one) and 定 (fixed/set) – together they mean 'set as one' or 'fixed', helping remember its meaning of certainty and definiteness.

📝 Usage Notes

Used in both formal and informal contexts, in spoken and written Chinese. Common in promises, strong assertions, instructions, and expressions of necessity. For example, it's often used to assure someone (我一定会来) or to set a rule (你一定要小心).

📖 Grammar Points

Often placed before a verb (一定 + Verb) to modify it. Can be used in negative form as 不一定 (bù yídìng) meaning 'not necessarily' or 'not definitely'. Also used in structures like 一定要... meaning 'must...'.

🏯 Cultural Notes

In Chinese communication, using 一定 can convey strong commitment or politeness when making promises. However, 不一定 is often used to soften statements and avoid absolute assertions, reflecting a cultural tendency toward indirectness.

🔄 Similar Words

肯定 (kěndìng) also means 'definitely' but is slightly more emphatic and can be an adjective ('certain'). 必须 (bìxū) means 'must' and is stronger, focusing on necessity rather than just certainty.

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