英语不是我的母语。

English is not my native language.

English is not my first language.

English is not my mother tongue.

English isn't my first language.

Source: Tatoeba

Sentence Composition

1 英语 Yīngyǔ English (language)
=2 不是 bùshì
  1. no
  2. is not
  3. not
=2 不是 bùshi fault; blame
3 我 wǒ
  1. I
  2. me
  3. my
=4 的 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 pígéde "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. dì or di in poetry and songs
=4 的 dī a taxi; a cab (abbr. for 的士 dīshì)
=4 的 dí really and truly
=4 的 dì (bound form) bull's-eye; target
5 母语 mǔyǔ
  1. native language
  2. mother tongue
  3. (linguistics) parent language