cos

cos — conjunction

1. used in informal speech or writing instead of 'because' to introduce the reason

1.連接詞B1
釋義

used in informal speech or writing instead of 'because' to introduce the reason why something happens or why someone does something

例句

Owen stayed home from school cos he had a high fever and a sore throat.

cos + clause stating the reason

Kemi was smiling all afternoon cos she got the scholarship she applied for.

同義詞
  • because

    standard, neutral register; suitable for all contexts including formal writing

  • since

    more formal and slightly more distant in tone; often used in writing

  • as

    formal, common in written English; often begins the sentence

文法句型

cos + clause stating the reason

用法筆記

Common in casual texting, notes, and everyday conversation. Avoid 'cos' in formal essays, business writing, or academic papers — use 'because' or 'since' instead.

常見錯誤

❌Cos it is raining, I brought an umbrella.
✅I brought an umbrella cos it was raining.
💡'Cos' usually starts the second clause (after the result), not the first. But placing it first is also heard informally.
❌He left early cos of the traffic.
✅He left early cos the traffic was bad.
💡'Cos' is a conjunction that connects a full clause; use 'because of' before a noun phrase.

cos — noun

cos — abbreviation