Noun + 是 + Noun
Reach for this when you want to identify or define one thing as another — 'he is a doctor,' 'Beijing is the capital,' 'this is my friend.' 是 is the linking verb 'to be,' but it has a narrower job than English 'is': it only connects nouns to nouns. For 'is + adjective,' Chinese uses 很 + adjective directly, no 是 needed.
Structure
[NOUN A] 是 [NOUN B]
shì
How to Think About It
是 is a noun-to-noun equal sign. Both sides have to be nouns (or noun-like things). The moment one side becomes an adjective — 'he is tall,' 'I am tired' — 是 drops out and you just say 他很高, 我很累. Treating 是 like English 'is' and slotting it before every adjective is the single biggest grammar tell of a beginner.
Examples
他是老师。
Tā shì lǎoshī.
He is a teacher.
北京是中国的首都。
Běijīng shì Zhōngguó de shǒudū.
Beijing is the capital of China.
这是我朋友。
Zhè shì wǒ péngyǒu.
This is my friend.
Common Mistake
Learners insert 是 before adjectives because English 'is' covers both 'is a doctor' and 'is tall.' In Chinese, adjectives are predicate-like on their own and don't need 是.
他是高。
他很高。
Don't Confuse With
Noun + 很 + Adjective
Use this — never 是 — when the second piece is an adjective.
Noun + 在 + Place
Use 在 for location ('is at the office'), not 是.
Noun + 有 + Noun
Use 有 for possession or existence ('has / there is'), not identification.
Practice
她_____ 我妈妈。 (is)
Show answer
是
这个城市_____ 大。 (don't use 是)
Show answer
很
Arrange: 是 / 学生 / 他 / 一个 / 好
Show answer
他是一个好学生。
Translate: I am American.
Show answer
我是美国人。
Write a sentence identifying someone using 是.
Show answer
我哥哥是医生, 他在北京工作。
Hear It in Real Episodes
This pattern appears in 1 Fluentide episode: