因为

In a sentence

• 因为天气不好，我们取消了野餐。

  Because of the bad weather, we canceled the picnic.

  In this sentence, "因为" introduces the reason or cause for the action taken, which is canceling the picnic.

• 她学习非常努力，因为她想考上好大学。

  She studies very hard because she wants to get into a good university.

  Here, "因为" is used to explain the cause for the preceding statement, namely her diligent studying.

• 我们迟到了，因为交通堵塞。

  We were late because of a traffic jam.

  In this example, "因为" is used to provide the reason for the situation described, which is being late.