V + 了
Verb-了: completion of an action
HSK 2HSK 3.0 · 2
S + V + 了 + (quantity/attributive) + O
了 right after a verb marks a completed action; it is aspect, not tense, so it also works for the future: 下了课我去找你 'after class I'll come find you'. With an object, the object usually needs a number or modifier (我买了三本书) or a follow-up clause (我买了书就回家), otherwise the sentence feels unfinished. Negate with 没(有) + V and drop 了. Habitual past actions do not take 了: 以前我常常去那儿.
In every HSK paper; HSK 3–4 sentence ordering often tests where 了 goes.
Examples
我昨天买了两本书。
I bought two books yesterday.
他喝了一杯咖啡就走了。
He drank a cup of coffee and then left.
明天下了课我们去吃饭吧。
Let's go eat tomorrow after class.
我没看那个电影。
I didn't see that movie.
Exercises
1.我昨天看 一个很好看的电影。
2.The negative form of 我吃了早饭 is:
3.以前他常常 那家饭馆吃饭。
4.明天下 班，我给你打电话。