你必須認真學習。

You must study hard.

Source: Tatoeba

Sentence Composition

=1 你 nǐ you (informal, as opposed to courteous 您 nín)
=1 你 nǐ you (Note: In Taiwan, 妳 is used to address females, but in mainland China, it is not commonly used. Instead, 你 is used to address both males and females.)
2 必須 bìxū
  1. to have to
  2. must
  3. compulsory
  4. necessarily
3 認真 rènzhēn
  1. conscientious
  2. earnest
  3. serious
  4. to take seriously
  5. to take to heart
4 學習 xuéxí
  1. to learn
  2. to study