Subject + 是 + Noun
This is the most basic sentence in Chinese — 'A is B.' Use 是 (shì) to identify or define one noun as another: a name, a profession, a nationality, a category. The subject sits first, 是 links it, and the noun follows. That's the whole pattern. Works for facts, introductions, descriptions of identity. Crucial point: 是 connects nouns to nouns. It does NOT come before adjectives — use 很 for those.
Structure
[SUBJECT] 是 [NOUN]
[SUBJECT] shì [NOUN]
How to Think About It
是 is for identity, not description. 'He is a teacher' = 他是老师 (noun) → 是. 'He is tall' = 他很高 (adjective) → 很. The rule is simple: if the second slot is a thing (老师, 中国人, 苹果), use 是. If it's a quality (高, 累, 漂亮), use 很. Mixing the two is the most common beginner error, and unlearning it takes most learners several months.
Examples
我是学生。
Wǒ shì xuésheng.
I am a student.
他是我哥哥。
Tā shì wǒ gēge.
He is my older brother.
这是一本书。
Zhè shì yì běn shū.
This is a book.
Common Mistake
Learners use 是 with adjectives, copying English 'is + adjective.' Chinese treats adjectives as their own verbs — they don't need 是. Use 很 (or another adverb) instead.
她是漂亮。
她很漂亮。
Don't Confuse With
很 + Adjective
Use 很 (not 是) when the second slot is an adjective. 是 = noun; 很 = adjective. This is the line.
Subject + 在 + Place
Use 在 for location, not 是. '他在家' (he's at home), not '他是在家.'
Subject + 有 + Object
Use 有 for possession or existence ('I have a dog'). 是 is identity. '我是一只狗' would mean 'I am a dog,' not 'I have a dog.'
Practice
我 ___ 美国人。
Show answer
是
他 是 ___。 (doctor)
Show answer
医生
Arrange: 老师 / 我的 / 中国人 / 是
Show answer
我的老师是中国人。
She is my friend.
Show answer
她是我的朋友。
Write one sentence introducing yourself using 是.
Show answer
我是一名工程师，也是一个爸爸。
Hear It in Real Episodes
This pattern appears in 4 Fluentide episodes:
他是一个外国人。
他是中国人。 — He is Chinese.
首相是英国的领导人