Comparing "kending" "queding" and “yiding"

If you look up 肯定 (kěndìng), 确定 (quèdìng) and 一定 (yīdìng) in the dictionary, they all have similar meanings, like "certain" or "surely." However, using them correctly in a sentence is a bit more complicated.

Word Overview

肯定 can be a verb, an adjective and an adverb. It often has a subjective, affirmative feel to it. It relates to approval and affirmation.

确定 can be a verb or an adjective, or, less commonly, an adverb of the form "确定 + 地 + Verb." More objective in tone, it is for deciding firmly and confirming decisions.

一定 can be an adjective or an adverb. It cannot be used as a verb. As an adverb, it is often used in commands, or as an adjective to refer to a "particular" something.

肯定 and 确定 as Verbs

Structure with 肯定

肯定 can express that something approval or affirmation, often used when a superior evaluates subordinates. When used this way, it should be followed directly by a noun or a phrase.

肯定 + Noun / Noun Phrase

肯定 can also be used to express "I am sure." When used this way it is usually a clause at the end of a sentence.

Subj. + (敢)肯定 + Sentences

Examples with 肯定

• 老板 肯定 了 我们 团队 的 工作。Lǎobǎn kěndìng le wǒmen tuánduì de gōngzuò.The boss approved our team's work.
• 如果 想 让 别人 肯定 你，你 就 要 好好 做。Rúguǒ xiǎng ràng biérén kěndìng nǐ, nǐ jiù yào hǎohāo zuò.If you want others to approve of you, you have to do good work.
• 我 敢 肯定 这 就 是 他的 声音。Wǒ gǎn kěndìng zhè jiùshì tā de shēngyīn.I'm quite sure that this is his voice.

Structure with 确定

确定 has the meaning of "confirm" or "determine," and you may add a verb phrase after 确定 to indicate that something is already decided. In a question, 确定 can be used to ask if someone is "sure" or "certain."

确定 + Phrase / Sentence

Examples with 确定

• 我们 还 没有 确定 什么 时候 开始。Wǒmen hái méiyǒu quèdìng shénme shíhou kāishǐ.We still haven't decided when to start.
• 已经 确定 了 三 个 人，还 差 一 个。Yǐjīng quèdìng le sān gè rén, hái chà yī gè.Three people have already been confirmed, and one more is needed.
• 你 确定 他 是 我们 要 找 的 人 吗？Nǐ quèdìng tā shì wǒmen yào zhǎo de rén ma?Are you certain he's the person we should look for?

Common Mistakes

• 我们 要 先 肯定 一 个 形式 才 能 开始 做。In this sentence, 肯定 needs to be followed by a noun or a noun phrase.Wǒmen yào xiān kěndìng yī gè xíngshì cái néng kāishǐ zuò.
• 我们 要 先 确定 一 个 形式 才 能 开始 做。Wǒmen yào xiān quèdìng yī gè xíngshì cáinéng kāishǐ zuò.We'll have to decide on a design before we can start working.

• 老板 肯定 了 最近 我 很 努力。In this sentence, "肯定" needs to be followed by a noun or noun phrase.Lǎobǎn kěndìng le zuìjìn wǒ hěn nǔlì.
• 老板 肯定 了 我 最近 的 努力。By changing the word order, we get a noun phrase instead of a verb phrase.Lǎobǎn kěndìng le wǒ zuìjìn de nǔlì.The boss approved of my recent hard work.

肯定 and 一定 as Adverbs

肯定 and 一定 can both be adverbs, and the grammar structures for both are similar. 肯定 emphasizes more of a subjective judgment or assurance. 一定 sometimes carries a bossy air, useful when issuing a command.

Structure with 肯定

肯定 + Adj. / Verb

Examples with 肯定

• 他 肯定 还 没 起床，因为 他 的 手机 现在 还 没 开机。Tā kěndìng hái méi qǐchuáng, yīnwèi tā de shǒujī xiànzài hái méi kāijī.He definitely hasn't gotten out of bed yet， because his phone is still off.
• 这 次 我 肯定 不 骗 你，骗 你 是 小 狗，好 吧？The idiom 骗你是小狗 literally means "to deceive you is to be a small dog." It doesn't have a good English equivalent.Zhè cì wǒ kěndìng bù piàn nǐ, piàn nǐ shì xiǎogǒu, hǎo ba?I'm not lying this time. Cross my heart.

Structure with 一定

一定 + Adj. / Verb

Examples with 一定

• 明天 你们 一定 要 来。Míngtiān nǐmen yīdìng yào lái.You guys definitely have to come tomorrow.
• 一定 要 小心。Yīdìng yào xiǎoxīn.You've absolutely got to be careful.

Common Mistakes

• 你们 肯定 要 去 听 我 的 演唱会。Since it's a command, "肯定" is not appropriate.Nǐmen kěndìng yào qù tīng wǒ de yǎnchàng huì.
• 你们 一定 要 去 听 我 的 演唱会。Nǐmen yīdìng yào qù tīng wǒ de yǎnchàng huì.You guys totally have to go listen to me in concert.

肯定, 确定, and 一定 as Adjectives

Structures

All three of these can be placed before a noun as adjectives.

肯定 / 确定 / 一定 + （的 +） Noun

But when used in this grammar structure, you must clearly differentiate the meanings of the words. 肯定 takes its verb meaning of "affirmative" or "approving," and 确定 takes its verb meaning of "confirmed" or "clearly decided," and 一定 as an adjective means "certain" or "particular."

Examples

• 如果 你 问 我 是 不 是 知道 这 件 事情，我 的 回答 是 肯定 的。Rúguǒ nǐ wèn wǒ shì bu shì zhīdào zhè jiàn shìqing, wǒ de huídá shì kěndìng de.If you ask me if I know about this, my answer will be affirmative.
• 请 给 我 一 个 确定 的 回答，不 要 总是 这么 模糊。Qǐng gěi wǒ yī gè quèdìng de huídá, bùyào zǒng shì zhème móhu.Please give me a definite response. Don't always be so vague.
• 我们 之间 要 保持 一定 距离。Wǒmen zhī jiān yào bǎochí yīdìng jùlí.We need to keep a certain distance between us.
• 这 件 事 和 他 有 一定 的 关系，不 能 都 怪 你。Zhè jiàn shì hé tā yǒu yīdìng de guānxì, bù néng dōu guài nǐ.He has a certain connection with this matter. We can't completely blame you.

Sources and further reading

Books

• HSK Standard Course 4上 (pp. 55) Anything Goes (无所不谈) →buy

• 对外汉语教学语法释疑201例 (pp. 180) [ →buy]

• 现代汉语八百词（增订本） (pp. 603) [ →buy]

• 卓越汉语－公司实战篇 (pp. 5) 卓越汉语－公司实战篇 →buy

Dictionaries

• 现代汉语词典（第5版） (pp. 776, 1594, 1136) 卓越汉语－公司实战篇 →buy

:Yes