Verb了...就... for “After …, (Then) …”
Put 了 after the first verb to mean “once this is done,” and 就 before the second verb for what follows: 我下了课就去图书馆.
句型
verb1 + 了 + (object)，(subject) + 就 + verb2
了 marks the first action as finished; 就 brings in what happens next. 就 can sometimes be left out.
我下了课就去图书馆。
When to use Verb了...就... for “After …, (Then) …”
This pattern packs two steps into one short sentence. 了 goes right after the first verb to show that action is (or will be) finished: 下了课 “after class is over,” 吃了饭 “after eating.” Then 就 comes before the second verb, after its subject if there is one: 我下了课就去图书馆 “I’ll go to the library after class.” Here 了 does not mean the past; it means “once … is done,” so the pattern works for the future, for habits and for the past. In relaxed speech 就 can be left out: 下了课我们去打球吧.
你到了北京就给我打电话。
Call me once you get to Beijing.
他每天吃了晚饭就去公园走走。
Every day after dinner he goes for a walk in the park.
买了票我们就进去吧。
Let’s go in once we’ve bought the tickets.
写完了作业，我就睡觉。
Once I’ve finished my homework, I’ll go to bed.
常见误区
- Put 了 right after the first verb: 吃了饭就走, not 吃饭就了走.
- Put 就 after the subject of the second part: 我就去, not 就我去.
- This 了 means “once it’s done,” not “in the past,” so 下了课就去 can be about tomorrow.
针对性练习
先练这个句式，再继续往下看。