既是……也是……
Reach for 既是...也是... when you want to say something fills two roles or has two qualities at once — 'it's both X and Y.' The pattern links two noun-phrase predicates equally; neither outweighs the other. Use it for things with dual nature: an opportunity and a challenge, a friend and a teacher, a problem and a chance. Common in commentary, definitions, and any time you want to capture a both-sides truth.
Structure
[SUBJECT] 既是 [ROLE_1] 也是 [ROLE_2]
jì shì... yě shì...
How to Think About It
既是...也是... weighs both roles the same. Use it only when the two predicates are genuinely on equal footing — both true, both important. If one role really matters more, 不仅是...更是... is the better fit. The pattern is almost always followed by nouns (是 needs a noun); for two adjectives or verbs, use 又...又... instead.
Examples
他既是我的老师, 也是我的朋友。
Tā jì shì wǒ de lǎoshī, yě shì wǒ de péngyou.
He's both my teacher and my friend.
学外语既是挑战, 也是乐趣。
Xué wàiyǔ jì shì tiǎozhàn, yě shì lèqù.
Learning a foreign language is both a challenge and a pleasure.
北京既是中国的首都, 也是一座古老的城市。
Běijīng jì shì Zhōngguó de shǒudū, yě shì yī zuò gǔlǎo de chéngshì.
Beijing is both China's capital and an ancient city.
Common Mistake
Learners drop the second 是 thinking it's redundant, but the pattern requires 是 on BOTH sides because each half is a separate 'be X' clause. Without the second 是, the sentence sounds broken.
他既是我的老师, 也我的朋友。
他既是我的老师, 也是我的朋友。
Don't Confuse With
又...又...
Use 又...又... for two adjectives or verbs (又便宜又好吃). 既是...也是... is specifically for two NOUN identities.
不仅是...更是...
Use 不仅是...更是... when the second role outweighs the first. 既是...也是... treats both as equal.
既...又...
既...又... (without 是) works for adjectives and verbs (既聪明又勤奋). 既是...也是... is the noun-predicate version.
Practice
他____我的老师, 也是我的朋友。
Show answer
既是
学外语既是挑战, ____乐趣。
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也是
Arrange: 一座 / 既是 / 北京 / 也是 / 古老的城市 / 中国的首都
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北京既是中国的首都, 也是一座古老的城市。
For the film industry, a long holiday is both an opportunity and a challenge.
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对电影行业来说, 长假期既是机会也是挑战。
Write a sentence using 既是...也是... describing someone with two roles.
Show answer
我的爸爸既是医生, 也是一位摄影师。
Hear It in Real Episodes
This pattern appears in 1 Fluentide episode:
Related Grammar Patterns
Acquire by listening
Hear 既是……也是…… in real Chinese, not in a textbook.
Fluentide picks the next news episode at your level, so this pattern shows up again and again in real context. The transcript marks it, the audio drills it. Free to start, no card.