Shi Sentences in Mandarin Chinese

In Brief

Use 是 (shì) when one person or thing is identified as another person, thing, or category: A 是 B. Negate it with 不是 (bú shì) and ask a yes–no question with 吗 (ma) or 是不是 (shì bu shì). Unlike English be, 是 normally does not connect a subject directly to an adjective.

Overview

The pattern A 是 B is one of the first sentence structures you meet at A1. It is used for identity and classification: “I am a student,” “That is my bag,” or “Today is Monday.” In grammatical terms, A is the subject (the person or thing being discussed), while B is the predicate (what the sentence says about that subject).

English uses forms of be in many different settings: I am a teacher, I am tired, I am at home, and I am twenty. Mandarin divides these meanings among different structures. 是 handles identity, category, and certain factual equations. Adjectives, locations, age, and possession follow other patterns.

That difference matters more than the English translation. Do not ask only whether an English sentence contains am, is, or are. Ask what the sentence is doing: is it identifying or classifying A as B? If so, 是 is likely appropriate.

How It Works

The basic pattern: A 是 B

The form of 是 never changes. Mandarin verbs do not conjugate for person or number, so 我是, 他是, and 他们是 all use exactly the same verb.

Part	Function	Example
A	subject: who or what you are talking about	我 wǒ, “I”
是	links A to an identity or category	是 shì
B	noun or noun phrase identifying A	学生 xuésheng, “student”
A 是 B	complete identity/classification statement	我是学生。 “I am a student.”

A noun phrase simply means a noun together with any words attached to it, such as “my teacher” or “a Chinese company.” Typical B elements include:

• a role or occupation: 她是医生。 “She is a doctor.”
• a nationality or group: 我是中国人。 “I am Chinese.”
• a relationship: 他是我哥哥。 “He is my older brother.”
• a named or pointed-out thing: 这是我的书。 “This is my book.”
• a day, date, or occasion: 明天是星期五。 “Tomorrow is Friday.”

Mandarin normally has no equivalent of English a/an before occupations. Say 我是老师, not a word-for-word version of “I am a teacher” with an extra article.

Negation with 不是

Put 不 (bù) directly before 是:

A + 不是 + B

• 他不是老师。 “He is not a teacher.”
• 这不是我的咖啡。 “This is not my coffee.”

Before the fourth-tone shì, 不 is normally pronounced with a rising tone: bú shì. It is still written 不是, and dictionaries generally list 不 as bù. Do not use 没 (méi) to make an ordinary 是 sentence negative.

Yes–no questions

There are two basic choices. The first adds the neutral question particle 吗 to a statement:

A + 是 + B + 吗？

• 你是学生吗？ “Are you a student?”

The second uses an A-not-A question, which presents the positive and negative alternatives:

A + 是不是 + B？

• 你是不是学生？ “Are you a student?”
• 这是不是你的书？ “Is this your book?”

These patterns ask essentially the same factual question. Do not normally combine them as 是不是……吗; choose one question frame.

Short answers usually repeat the relevant verb rather than using a universal word equivalent to English yes or no:

• 是。 “Yes; that is correct.”
• 不是。 “No; that is not the case.”
• 是，我是学生。 “Yes, I am a student.”
• 不是，我是老师。 “No, I am a teacher.”

Questions with question words

A question word stays where the missing information would appear. Mandarin does not move it to the beginning merely because the sentence is a question.

• 他是谁？ “Who is he?”
• 这是什么？ “What is this?”
• 哪位是王老师？ “Which person is Teacher Wang?”

Compare 他是我老师 (“He is my teacher”) with 他是谁？ The answer position after 是 becomes 谁 (“who”). Do not add 吗 to a sentence that already contains a question word such as 谁 or 什么.

Where English be does not become 是

The beginner rule is straightforward: use 是 before a noun or noun phrase that identifies or classifies the subject, but not as a general-purpose bridge before every kind of description.

Meaning	Natural Mandarin pattern	Example
identity/category	A 是 + noun phrase	她是医生。 “She is a doctor.”
quality	A + degree adverb + adjective	她很忙。 “She is busy.”
location	A + 在 + place	她在家。 “She is at home.”
age	A + number + 岁	她二十岁。 “She is twenty.”
possession	A + 有 + object	她有一本词典。 “She has a dictionary.”

In 她很忙, 很 (hěn) often acts as a natural link between the subject and adjective in a neutral statement. It does not always carry the strong English meaning “very.” A bare adjective can sound contrastive or context-dependent: 她忙，我不忙 means “She is busy; I’m not.”

Examples in Context

Mandarin	Pinyin	English	Note
我是中国人。	Wǒ shì Zhōngguó rén.	I am Chinese.	Classification by nationality
这是我的书。	Zhè shì wǒ de shū.	This is my book.	Identifying an object
他不是老师。	Tā bú shì lǎoshī.	He is not a teacher.	Negative with 不是
你是学生吗？	Nǐ shì xuésheng ma?	Are you a student?	Yes–no question with 吗
这是不是你的书？	Zhè shì bu shì nǐ de shū?	Is this your book?	A-not-A question
那个人是我哥哥。	Nà ge rén shì wǒ gēge.	That person is my older brother.	Identifying a relationship
李小姐是我们的经理。	Lǐ xiǎojiě shì wǒmen de jīnglǐ.	Ms. Li is our manager.	Role within a group
明天是星期五。	Míngtiān shì Xīngqīwǔ.	Tomorrow is Friday.	Day of the week
今天是我的生日。	Jīntiān shì wǒ de shēngrì.	Today is my birthday.	Occasion
他是谁？	Tā shì shéi?	Who is he?	谁 occupies the answer position
这是什么？	Zhè shì shénme?	What is this?	Asking for identification
哪个是你的杯子？	Nǎ ge shì nǐ de bēizi?	Which one is your cup?	Choosing among visible items
王老师也是北京人。	Wáng lǎoshī yě shì Běijīng rén.	Teacher Wang is also from Beijing.	也 comes before 是
我们都是新学生。	Wǒmen dōu shì xīn xuésheng.	We are all new students.	都 comes before 是
这里不是我的家。	Zhèlǐ bú shì wǒ de jiā.	This place is not my home.	Identity, not simple location

Common Mistakes

Adding 是 before an adjective

• Wrong: 她是很忙。
• Right: 她很忙。 “She is busy.”
• Why: 忙 is an adjective describing a quality. In an ordinary neutral description, Mandarin does not use 是 as the English-style copula (linking verb) before it.

Using 是 for location

• Wrong: 我是在家。 (as a neutral answer to “Where are you?”)
• Right: 我在家。 “I am at home.”
• Why: 在 expresses location by itself. 我是在家 can exist with special contrastive emphasis, but it is not the basic location pattern a beginner needs.

Negating 是 with 没

• Wrong: 他没是医生。
• Right: 他不是医生。 “He is not a doctor.”
• Why: The standard negative of 是 is 不是. 没 is used in other negative patterns, especially with 有 and completed events.

Combining two yes–no question patterns

• Wrong: 你是不是学生吗？
• Right: 你是学生吗？ or 你是不是学生？
• Why: 吗 and 是不是 are each sufficient to create the question. Using both is redundant in standard Mandarin.

Adding 吗 after a question word

• Wrong: 他是谁吗？
• Right: 他是谁？ “Who is he?”
• Why: 谁 already makes the sentence a question. Keep it in the position where the answer would go.

Translating English articles into the occupation phrase

• Wrong: trying to insert a separate word for a in 我是一个老师 whenever English says “I am a teacher.”
• Right: 我是老师。
• Why: Bare occupation nouns are normal after 是. 一个老师 is possible when the number or sense of “one/a particular teacher” matters, but it is not required by English a.

Usage Notes

Adverbs come before 是

Common adverbs normally precede the verb:

• 他也是学生。 “He is also a student.”
• 他们都是医生。 “They are all doctors.”
• 这只是一个建议。 “This is only a suggestion.”

This gives the useful pattern subject + adverb + 是 + noun phrase. With 都 (“all”), the subject is normally plural or refers to a set.

是 in dates and labels

是 is natural when equating one expression with another: today with a date, a person with a role, or an object with a label. In brief conversational answers, however, speakers may omit material that is obvious:

• 今天几号？——十二号。 “What date is it today? — The twelfth.”
• 你是哪国人？——加拿大人。 “What country are you from? — Canadian.”

The omitted 是 does not change the full underlying relationship; short answers simply avoid repeating predictable words.

Pronunciation and rhythm

是 is fourth tone, shì. In 不是, normal tone sandhi (a pronunciation change caused by neighboring tones) makes 不 sound like second-tone bú before the fourth tone: bú shì. In 是不是, the middle 不 is often light and unstressed in natural speech, but careful shì bu shì is a safe learner pronunciation.

Beyond the Basics / Advanced Use

You do not need to produce the following patterns at A1, but they explain examples that may otherwise seem to break the beginner rules.

Emphatic 是 before a description

Mandarin can place 是 before an adjective or another predicate for confirmation or contrast:

• 他是很忙，但是愿意帮你。 “He really is busy, but he is willing to help you.”
• 这个办法是不错。 “This method is indeed not bad.”

Here 是 emphasizes that the statement is true; it is not merely an obligatory equivalent of English is. The neutral beginner versions are 他很忙 and 这个办法不错.

The 是……的 construction

The frame 是……的 can highlight a detail of a known event, often the time, place, manner, or person involved:

• 我是昨天来的。 “It was yesterday that I came.”
• 这本书是在上海买的。 “This book was bought in Shanghai.”

Although it contains 是, this is a larger grammar construction, not a simple A 是 B identity sentence. Study it separately after you are comfortable with basic verb sentences and completed events.

Omitted 是 in noun-predicate sentences

Some noun predicates can appear without 是, especially age, price, dates, and informal statements of quantity:

• 我二十岁。 “I am twenty.”
• 今天星期五。 “Today is Friday.”
• 这本书三十块。 “This book is thirty yuan.”

For days and dates, both 今天是星期五 and 今天星期五 may occur. The version with 是 makes the equation explicit; omission is common when the relationship is routine and clear. Age and price, however, normally use their own direct noun-predicate patterns rather than requiring 是.

是 as agreement or correction

On its own, 是 can confirm a claim: “Yes,” “That’s right,” or “It is.” It can also introduce a correction through 不是……是……:

• 不是星期四，是星期五。 “It isn’t Thursday; it’s Friday.”
• 他不是我哥哥，是我弟弟。 “He isn’t my older brother; he’s my younger brother.”

This paired contrast is common and useful because it clearly replaces one identity with another.

Practice Tips

1. Sort English be sentences by meaning. Take ten sentences with am/is/are and label them “identity,” “quality,” “location,” “age,” or “possession.” Use 是 only for the identity group; use 很 + adjective, 在, the age pattern, or 有 for the others.
2. Build three versions of each identity sentence. Start with 她是医生, then make 她不是医生 and 她是医生吗？ Repeat with people, objects, days, and roles until the changes feel automatic.
3. Answer with the verb you hear. Have a partner or recording ask 是不是 questions. Respond first with 是 or 不是, then add a full sentence. This trains natural Mandarin answers instead of relying on a one-size-fits-all translation of English yes and no.

Related Concepts

• Prerequisite: Basic Sentence Structure — review the normal subject–predicate order that 是 sentences build on.