你要改善一下你的英語。

You have to polish your English.

Source: Tatoeba

Sentence Composition

=1 you (informal, as opposed to courteous nín)
=1 you (Note: In Taiwan, is used to address females, but in mainland China, it is not commonly used. Instead, is used to address both males and females.)
=2 yāo (bound form) to demand; to coerce
=2 yào
  1. to want; to need; to ask for
  2. will; shall; about to
  3. need to; should
  4. if (same as 要是 yàoshi)
  5. (bound form) important
=2 yǎo
  1. (archaic) alternative form of (yǎo)
  2. alternative form of (yǎo)
  3. used in 要褭要袅
3 改善 gǎishàn to make better; to improve

classifier:

4 一下 xià
  1. (after a verb) a bit; a little (indicating brief duration, or softening the tone, or suggesting giving sth a try)
  2. all at once; suddenly
=5 you (informal, as opposed to courteous nín)
=5 you (Note: In Taiwan, is used to address females, but in mainland China, it is not commonly used. Instead, is used to address both males and females.)
=6 de
  1. of; ~'s (possessive particle)
  2. (used after an attribute when it modifies a noun)
  3. (used at the end of a declarative sentence for emphasis)
  4. (used after a noun, verb or adjective to form a nominal expression, as in 皮革的 de "one made of leather" or 跑堂儿的 pǎotángrde "a waiter (literally, one who runs back and forth in a restaurant)" or 新的 xīnde "new one")
  5. also pr. or di in poetry and songs
=6 a taxi; a cab (abbr. for 的士 shì)
=6 really and truly
=6 (bound form) bull's-eye; target
7 英語 Yīng English (language)