是 + noun + 的
Reach for this when you want to label or classify something — 'X is the [noun] kind / X belongs to [noun].' The frame puts a descriptor noun between 是 and 的, turning the noun into a classifying adjective. 小明是三年级的学生 doesn't just say he is a student — it pins down which grade. Use it any time you want to say someone or something is a specific type, member, or version.
Structure
[SUBJECT] 是 [NOUN/PHRASE] 的 [HEAD NOUN]
shì... de...
How to Think About It
The 的 turns whatever noun you put before it into a modifier. 三年级 is 'third grade'; 三年级的学生 is 'a third-grade student.' Without 的, the two nouns just sit next to each other and the listener doesn't know whether you mean 'third grade' or 'third-grade student.' 的 is the glue that makes the first noun describe the second.
Examples
小明是三年级的学生。
Xiǎo Míng shì sān niánjí de xuéshēng.
Xiao Ming is a third-grade student.
这是我哥哥的书。
Zhè shì wǒ gēge de shū.
This is my older brother's book.
她是法国的老师。
Tā shì Fǎguó de lǎoshī.
She is a French teacher (a teacher from France).
Common Mistake
Learners drop 的 because in English you say 'a third-grade student' with nothing between the words. In Chinese, when one noun modifies another and the modifier is longer than one syllable, 的 is required — without it the sentence sounds incomplete.
小明是三年级学生。
小明是三年级的学生。
Don't Confuse With
是...的 (emphasis)
The other 是...的 construction emphasizes WHEN, WHERE, or HOW something happened: 我是昨天来的 ('I came yesterday'). That version has no noun between — it wraps the verb phrase.
Noun + Noun (no 的)
Some short fixed compounds skip 的: 中国学生, 男孩子. Use the bare form only for tight common pairings; once the modifier is descriptive or longer, put 的 back.
有 + Noun
有 says something EXISTS or possesses; 是...的 says what KIND it is. 我有妹妹 = 'I have a sister.' 她是我的妹妹 = 'She is my sister.'
Practice
小明 ___ 三年级的学生。
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是
这是我妈妈 ___ 手机。
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的
Arrange: [是 / 的 / 我 / 学生 / 大学]
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我是大学的学生。
Translate to Chinese: 'He is a Chinese teacher.'
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他是中文的老师。
Write one sentence using 是 + [noun] + 的 + [noun] to describe yourself.
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Example answer: 我是北京的工程师。 (I am an engineer from Beijing.)
Hear It in Real Episodes
This pattern appears in 1 Fluentide episode: