"Please switch off the air conditioner."

Translation: 请把空调关了。

[albizgil]

what's wrong with this one?
"清关空调"

[David.A.Weldon]

Why is there a 了 ？the action isnt complete yet

[DariusLee3]

If you put your mouse over the word 了, you see that it is an interjection in this case. Wikipedia says that "in linguistics, an interjection is a word or expression that occurs as an utterance on its own and expresses a spontaneous feeling or reaction"

Meanwhile, it is weird to say it without the 了 because the sentence would feel incomplete. Instead of using 关了, you use 关 and a preposition e.g. 关掉 or 关上 to have a complete verb

[R7fi9dwS]

I have the same question. In this case, I learned to put 上 after 关。I understand that the sentence should not end with 关，but still 觉得用“了”很奇怪。

[hoanganh43]

Same question

[Gabrielle145359]

I think in this case, 了 is expressing the "new situation" of the air conditioner being off (that will be a new situation, because the air conditioner is on now.)
However, you need to put something where the 了 is in this sentence. When you use the 把 sentence structure, you can't end it with a single character verb. There has to be some kind of complement after the verb. So 了 is filling a grammatical need here.

[Jan863662]

Hmm. But Chinese has plenty of interjections. Why not end in a ba or an a? None of those are normally associated with completion.

[R7fi9dwS]

I wrote 关上 and it was rejected

[freshsneezes]

Would it also be acceptable to use "冷气" in this case? And is using one word over the other a regional thing or just a preference?