湯姆不是老師，是學生。

Tom isn't a teacher. He's a student.

Source: Tatoeba

Sentence Composition

1 湯姆 Tāngmǔ Tom (name)
=2 不是 bùshì
  1. no
  2. is not
  3. not
=2 不是 bùshi fault; blame
3 老師 lǎoshī teacher

classifiers: 個, 位
=4 是 shì
  1. to be (followed by substantives only)
  2. correct; right; true
  3. (respectful acknowledgement of a command) very well
  4. (adverb for emphatic assertion)
=4 是 shì variant of 是 shì
=5 學生 xuésheng
  1. student
  2. schoolchild
=5 學生 xuéshēng
  1. disciple; follower (Classifier: 位 m)
  2. student; pupil (Classifier: 位 m)