Introduction

是……的 (shì…de) sentences often confuse learners of Chinese. At first glance, the structure looks simple, yet in practice it is used only in very specific situations. Many learners memorise it as a fixed sentence pattern, treating it as a special type of sentence, without really understanding why it is used in some contexts but not in others.

In this article, we focus on the 是……的 construction: its meaning, structure, negative and interrogative forms, object placement, and the most common mistakes learners make. The goal is not just to show how the structure looks, but to clarify what it actually does.

What the 是……的 sentences really means and what it is used for

Sentences with 是……的 are not used to indicate that something happened in the past. Instead, they are used to highlight or emphasise specific information about an action that has already been completed.

In other words:

• the action itself is already known or taken for granted,
• the speaker wants to emphasise how, when, where, with whom, or under what circumstances it happened.

Example:

• 我昨天买了这本书。(Wǒ zuótiān mǎi le zhè běn shū.) – I bought this book yesterday.
• 我是昨天买的这本书。(Wǒ shì zuótiān mǎi de zhè běn shū.) – I bought this book yesterday.

In the second sentence, the focus is on the time when the book was bought, not on the fact that the purchase took place.

是……的 sentences: the basic structure

是 is placed before the element we want to emphasise, while 的 appears at the end of the sentence. The most common pattern looks like this:

subject + 是 + emphasised element + verb + 的 (+ object)

Example:

• 他是坐飞机来的。(Tā shì zuò fēijī lái de.) – He came by plane.

Here, the focus is on the means of transport, not on the act of coming itself.

It is important to note that in 是……的 sentences:

• the verb does not change,
• aspect particles such as 了 (le) are not used,
• the focus is always on the element placed between 是 and the verb.

What can be emphasised in the 是……的 sentences

Time

• 我是三年前开始学中文的。(Wǒ shì sān nián qián kāishǐ xué Zhōngwén de.) – I started learning Chinese three years ago.

Place

• 他是在北京认识她的。(Tā shì zài Běijīng rènshi tā de.) – He met her in Beijing.

Manner / means

• 我是坐地铁去的。(Wǒ shì zuò dìtiě qù de.) – I went by underground.

Participants / circumstances / purpose

• 她是跟朋友一起去的。(Tā shì gēn péngyou yìqǐ qù de.) – She went with friends.
• 这件事是他决定的。(Zhè jiàn shì shì tā juédìng de.) – He was the one who made the decision.
• 他们是来学习中文的。(Tāmen shì lái xuéxí Zhōngwén de.) – They came to study Chinese.

Negative form in 是……的 sentences

The negative form is created using 不, placed directly before 是.

Examples:

• 我不是昨天来的。(Wǒ bú shì zuótiān lái de.) – I didn’t come yesterday.
• 他不是一个人做的。(Tā bú shì yí gè rén zuò de.) – He didn’t do it alone.

The negation does not deny the action itself, but rather the specific information being emphasised.

Question form in 是……的 sentences

Questions are formed using the affirmative–negative pattern 是不是……的.

Example:

• 他们是不是在北京工作的？(Tāmen shì bú shì zài Běijīng gōngzuò de?) – Do they work in Beijing?

Object position in the 是……的 sentences

This is one of the most common sources of confusion for learners.

When the object is a pronoun

If the object is a pronoun, it always appears before 的.

Example:

• 我是昨天认识他的。(Wǒ shì zuótiān rènshi tā de.) – I met him yesterday.

When the object is a concrete noun

If the object is a specific noun or noun phrase, it most often appears after 的.

Example:

• 我是昨天买的这本书。(Wǒ shì zuótiān mǎi de zhè běn shū.) – I bought this book yesterday.

When the object is a place

If the object refers to a place, it can appear either before or after 的.

Examples:

• 他是开车去公司的。or 他是开车去的公司。(Tā shì kāichē qù gōngsī de / Tā shì kāichē qù de gōngsī.) – He drove to work.
• 妈妈是坐火车去上海的。or 妈妈是坐火车去的上海。(Māma shì zuò huǒchē qù Shànghǎi de / Māma shì zuò huǒchē qù de Shànghǎi.) – Mum went to Shanghai by train.

When 是……的 is not used

The 是……的 construction is not used:

• to describe general habits,
• for actions that are ongoing or still in progress,
• for neutral narration without emphasis.

Example of incorrect usage:

• 我是每天喝咖啡的。(Wǒ shì měitiān hē kāfēi de.)

Correct sentence:

• 我每天喝咖啡。(Wǒ měitiān hē kāfēi.)

Here, there is no specific information being highlighted, the sentence simply describes a habit.

Conclusion

The 是……的 construction is not another past tense form, but a way of highlighting details about an action that has already been completed. Once it becomes clear that its core function is focus, not time, it becomes much easier to understand when it should be used—and when it should not.

Because of its very specific function, 是……的 deserves special attention in the study of Chinese grammar.

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