了
le
Expressing "already" with just "le"
A bare 了 can carry "already" on its own, without 已经.
Subj. + Verb Phrase + 了
How it works
— 你应该问老师。— 我问了。 "You should ask the teacher." "I already did." The 了 alone answers the implied "you haven't".
Adding 已经 is possible but often unnecessary; the 了 does the work in context.
Examples
wǒ wèn le
我问了。
I already asked.
qián wǒ gěi tā le
钱我给他了。
I've given him the money.
zuò yè wǒ xiě wán le
作业我写完了。
I've finished the homework.