"I have already finished lunch."

Translation: 我已经吃完午饭。

[EricLuo4]

It's not wrong, but I think: 我已经吃完午饭了 would sound better

[SmithUA01]

no "了"?

[jacobareed]

Why not accept 我已经吃完了午饭 like similar exercises?

[LaBiciEsMia]

I wondered if that was because it includes 已经, but the 已经。。了 pattern seems to be standard usage.

https://resources.allsetlearning.com/chinese/grammar/Expressing_%22already%22_with_%22yijing%22

Is this another bad Duolingo question?

[ThieumL]

Chinese has a simple rule that states that you can remove all the unecessary stuff. 已经 and 完 already imply something has been done and finished, you are free to add 了 or not, but it is completely unecessary. Put it or leave it, both ways are right.