Comparing "dui" and "duiyu"

对 (duì) and 对于 (duìyú) can be confusing because they overlap quite a bit in usage, but they are not entirely interchangeable.

对 and 对于 Are Equivalent When Used as a Preposition

When 对 and 对于 are used as prepositions to modify a verb, they are basically the same. As a matter of fact, when used this way 对 is just the simplification of 对于! 对于 sounds a bit more formal.

Structure

对／对于 + Object + Verb

Examples

In the following example sentences, 对 and 对于 are interchangeable.

• 对(于) 这 种 事情，你 有 什么 看法？Duì(yú) zhè zhǒng shìqing, nǐ yǒu shénme kànfǎ?As for this kind of thing, what's your perspective?
• 我 对(于) 上海 从来 没 喜欢 过 也 没 讨厌 过。Wǒ duì(yú) Shànghǎi cónglái méi xǐhuan guo yě méi tǎoyàn guo.I've never liked or disliked Shanghai.

对 Is More Versatile within a Sentence

Both 对 and 对于 can be placed before or after the subject in a sentence. Unlike 对, however, 对于 cannot be placed after the adverb in the middle of a sentence.

Examples

They can both go in the very front:

• 对 这 个 问题，我们 都 很 感兴趣。Duì zhège wèntí, wǒmen dōu hěn gǎn xìngqù.
• 对于 这 个 问题，我们 都 很 感兴趣。Duìyú zhège wèntí, wǒmen dōu hěn gǎn xìngqù.

They can both go right after the subject:

• 我们 对 这 个 问题 都 很 感兴趣。Wǒmen duì zhège wèntí dōu hěn gǎn xìngqù.
• 我们 对于 这 个 问题 都 很 感兴趣。Wǒmen duìyú zhège wèntí dōu hěn gǎn xìngqù.

Only one can go right before the predicate:

• 我们 都 对 这 个 问题 很 感兴趣。Wǒmen dōu duì zhège wèntí hěn gǎn xìngqù.
• 我们 都 对于 这 个 问题 很 感兴趣。Wǒmen dōu duìyú zhège wèntí hěn gǎn xìngqù.

All of the above examples mean "we are all interested in this problem."

对 Can be Used as a Verb

As a Verb Meaning "to face"

When 对 is used as a verb, it expresses "to face" or "to point at," and you will often see it in the form 对着. It can also be used in verb phrases which refer to "matching," like 对上 and 对不上.

Subj. + 对着 ／ 对上 ／ 对不上

Examples

• 枪口 不 要 对着 人。Qiāng kǒu bùyào duìzhe rén.Don't point the gun at people.
• 我 喜欢 对着 镜子 笑。Wǒ xǐhuan duìzhe jìngzi xiào.I like to laugh at the mirror.
• 这 两 个 数字 对上了 吗？Zhè liǎng gè shùzì duì shàng le ma? Are these two data aligned?
• 这 两 本 账 对不上。Zhè liǎng běn zhàng duì bu shàng.These two accounts don't match up.

对 Can Be Used with Emotional Adjectives

To indicate to whom an emotional response is directed, you can use 对 but not 对于.

Structure

A + 对 + B + Adj.

Examples

• 他 对 工作 很 认真。Tā duì gōngzuò hěn rènzhēn.He treats his work very seriously.
• 我 的 男 朋友 对 我 很 好。Wǒ de nán péngyǒu duì wǒ hěn hǎo.My boyfriend is very good to me.

Common Mistakes

• 我们 都 对于 这个 人 很 怀疑。Wǒmen dōu duìyú zhège rén hěn huáiyí.
• 我们 都 对 这个 人 很 怀疑。Wǒmen dōu duì zhège rén hěn huáiyí.
• 他 对于 工作 很 认真。Tā duìyú gōngzuò hěn rènzhēn.
• 他 对 工作 很 认真。Tā duì gōngzuò hěn rènzhēn.

Example Dialog

• A: 对于 这 件 事，你 怎么 看？A: Duìyú zhè jiàn shì, nǐ zěnme kàn?What do you think about this?
• B: 我 对 她 很 了解，她 不 会 这么 做 的。B: Wǒ duì tā hěn liǎojiě, tā bù huì zhème zuò de.I understand her completely. She can't do it like this.

Sources and further reading

Books

• 对外汉语教学语法释疑201例 (pp. 81) [ →buy]
• 现代汉语八百词（增订本） (pp. 463) [ →buy]
• 卓越汉语－公司实战篇 (pp. 134) 卓越汉语－公司实战篇 →buy

Dictionaries

• 现代汉语词典（第5版） (pp. 343, 344) 卓越汉语－公司实战篇 →buy

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