用法：
1.用作連系動(dòng)詞，其后可接名詞、形容詞、過(guò)去分詞等作表語(yǔ)：
He became a teacher at (the age of)17.他17歲就當(dāng)了老師。
The weather became warmer.天氣變得暖和起來(lái)。
注意：其后接過(guò)去分詞時(shí)，可表示被動(dòng)或結(jié)果；但表示被動(dòng)時(shí)，其后一般不接by短語(yǔ)。比如不說(shuō)：
Soon the room became crowded bystudents.
2.become是終止性動(dòng)詞，因此要表示“成為…有多長(zhǎng)時(shí)間”，英語(yǔ)不能將become與表示一段時(shí)間的詞或短語(yǔ)連用：
他成為老師有十年了。
正：He became a teacher ten years ago.
正：It’s ten years since he became a teacher.
誤：He has become a teacher for ten years.
3.become之后一般不接不定式表示“逐漸…”(此時(shí)可用come/begin＋不定式)：
正：He began [came] to like English.他開(kāi)始喜歡英語(yǔ)起來(lái)。
誤：He became to like English.
正：He became ill yesterday.他昨天病了。
誤：He became to be ill yesterday.
4.用于習(xí)語(yǔ)becomeof,表示“發(fā)生”、“遭遇”等(常與what連用)：
What has become of the girl?這個(gè)女孩后來(lái)怎樣了?
I don’t know what will become of me if I fail this time.要是我這次不成功，我不知我會(huì)怎么樣。