她是我的英文老师。

Tā shì wǒde Yīngwén lǎoshī.

She is my English teacher.

她在学校工作，是个老师。

Tā zài xuéxiào gōngzuò, shì ge lǎoshī.

She works at a school, (she's) a teacher.

我老师每天都帮助我复习。

Wǒ lǎoshī měitiān dōu bāngzhù wǒ fùxí.

My teacher helps me review every day.