When should I use "了" in “把”字句 and where should it be placed?

Question

A completed action with 把 sentence - I saw some sentences with 了 and some without 了. Is there a rule?

我把课本放在桌子上。

他把病人送到医院。

but

姐姐把照片存在电脑里了。

我把我的新书丢在公共汽车上了

and is there a difference where the 了 is placed?

小明把礼物送给了妈妈。

Answer 1

Compare these sentences:

1. 我把课本放在桌子上。

2. 他把病人送到医院。

3. 我把课本放在桌子上了。

4. 他把病人送到了医院。

Sentence 1 and 2 don't indicate the tense and tell whether those events happen in the present, past or future. Sentence 3 and 4 clearly indicate those events happened in the past because they have 了.

Practically, you could put 了 after verb. If you see a prepositional phrase in the end, you can attach 了 at the end of the prepositional phrase or sentence.

For example,

1. 我把课本放在桌子上了。 在桌子上 is a prep phrase, so you attach 了 at the end. The same thing for 姐姐把照片存在电脑里了。 我把我的新书丢在公共汽车上了.

2. 他把病人送到了医院。in this case, it doesn't have any prep phrase in the end, so you can put 了 after the verb 送到. In 小明把礼物送给了妈妈。送给 is the verb, so you can put 了 after it.

Answer 2

"了" Equivalent to the past perfect tense,Means the end of things, the completion of actions

For example：

我把面包吃了!

If it is not added, it is a command, a request, a recommendation

For example：

你把电脑打开。

Answer 3

1. 我把手機賣了。
2. 我要把手機賣了。
3. 我要把手機賣。

Sentence 1, the action completed. Sentence 2, the action seems haven't been completed. (not happen yet) Sentence 3, it's a wrong sentence.

In this case, why should we use 了 in 1 and 2? Is it any chance that sometimes we must use 了 because of the specific verb or there is other reason? I would appreciate it if anyone can share your insight here.