jiàoshì lǐ de lājītǒng mǎn le, tā shùnbiàn bǎ lājī ná dào lóuxià.

The trash can in the classroom was full, so he took the trash downstairs on the way.

Breakdown of jiàoshì lǐ de lājītǒng mǎn le, tā shùnbiàn bǎ lājī ná dào lóuxià.

• 他tā: he
• 了le: change-of-state particle
• 把bǎ: disposal marker

Questions & Answers about jiàoshì lǐ de lājītǒng mǎn le, tā shùnbiàn bǎ lājī ná dào lóuxià.

Why is there no 是 (“to be”) before 满了? Why not 垃圾桶是满了?

In Chinese, many adjectives also act as stative verbs. 满 here is a verb meaning “to be full,” so 垃圾桶满了 literally means “the trash can has become full / is full now.”

You normally don’t use 是 before this kind of predicate:

• ✔ 垃圾桶满了。= “The trash can is (now) full.”
• ✘ 垃圾桶是满了。

是 + adjective is used in specific contrasts or emphatic structures (like “it is full, but…”), not for a simple description.

What exactly does 了 mean in 满了? Is it past tense?

Here 了 marks a change of state, not simple past tense.

• 满 = (to be) full
• 满了 = “(has) become full,” “is now full (but wasn’t before).”

So 了 is telling you that the situation has reached a new state: the trash can wasn’t full before, and now it is. It often implies the event already happened, so it often refers to the past, but its core function here is change-of-state, not “past tense” in the English sense.

How does 的 work in 教室里的垃圾桶?