Expressing duration with "le"
Saying how long you did something for in Chinese can seem tricky, as there is no preposition as in English. Instead it's all about word order:
Subject + Verb + 了 + Duration + Object
So 了 is placed after the verb (to indicate that the action is completed), followed by the duration. This is how you talk about the duration of completed actions.
- 他 在 北京 住 了 两 年。
- 我 上 了 半 个 小时 网。
- 我 喝 了 三 个 小时 啤酒。
Note that the pattern above is to express the duration of completed actions which are no longer in progress. To indicate that the action is still in progress, use a slightly different pattern.