Use of 了with past sentences

[Tony24]

Hi everyone!

lately I’ve been studying 了 and all of its uses.

I must admit that I still don’t get whether it is always used with past sentences or can be omitted, as I’ve seen more than one phrase without it.

e.g. 昨天我买三本书。and 昨天我买了三本书。

are both of them fine ?

 

Any help would be very appreciated

[timacro]

You should choose 昨天我买了三本书.

了 can be used next to many verbs to represent past tense or perfect tense.

e.g.

1. 我做了个梦

2. 这事儿已经黄了

3. 饭做好了

 

And the last challenge: ?

为了了却她的心愿，他花光了积蓄，瞬间感到了无生趣了。

[Shelley]

I suggest you have a look at Chinese Grammar Wiki here https://resources.allsetlearning.com/chinese/grammar/

 

Also remember that you will learn different usages according the level you are at, the more difficult uses will come later, learn the ones at your level well and progress up till you understand all the uses well.

[edelweis]

I think you can omit 了 in some circumstances ?

昨天我买三本书的时候就发现我的信用卡丢掉了。

前天你买了四本书，昨天买三本书，今天买六本书，明天呢？

 

maybe someone can confirm whether these sentences are correct?

[Publius]

You should rid yourself of the notion that 了 is associated with the past.

Chinese does not have a tense system. The "when" of an action is either expressed explicitly using an adverb or implied by the context.

What Chinese does have is an aspect system. These two concepts are often confused. Tense is the "when". It defines the location of an event on the temporal axis. Aspect is the "how". It describes the internal state of an event: whether it's completed, continuing, or repetitive, etc.

English uses a mixed tense-aspect system. "I was thinking" -- "was" is past tense, it sets the stage at a point prior to the speech event itself; "thinking" is progressive aspect, it signifies that the action/process in question was ongoing at that particular point in time. "I have lost my mind" -- "lost" is perfect aspect, the loss is complete; "have" is present tense, although the loss happened in the past, we're more focused on its impact on the present, i.e. that I cannot think.

Chinese verbs are never marked for tense, but are regularly marked for aspect. You need to dissociate 了 from the past tense. Consider this sentence: 吃了饭再走吧！ This is an imperative. All the actions (eat and leave) haven't happened yet. Why is there a 了? Because it helps establish the sequence of actions. "Leave" only when the "eat" is completed.

"I bought a book yesterday" -- this is simple past in English, the verb is unmarked for aspect, because from the English grammar's standpoint, that piece of information is either unimportant or obvious.

But in Chinese, the aspect is more important. In the statement 我昨天买了三本书, the action (buy) is complete, so the perfect aspect marker 了 is the natural choice. 了 is there not because it's a past action but because the action is complete.

If the action isn't complete, like in edelweis's first example 昨天我买三本书的时候就发现我的信用卡丢掉了, you cannot use 了 even if it's a past action. Hope this helps.

 

[stapler]

In addition to what everyone above said, you should also be mindful that 了 is also dropped when describing background information. I believe this is a particularly devilish point for beginners because it may give the impression that there is no clear and definite time to use 了.

 

For example, you could actually write " 昨天我买三本书 , 碰到了我好朋友”. In this sentence one verb (碰) has 了 and the other (买) doesn't, even though both actions are finished. In this sentence the action of bumping into your friend is being emphasised and the act of buying books is not important.

 

As a beginner it's probably not worth worrying about this. I just wanted to flag it so you are aware that is a possibility.

 

[timacro]

Agree with the opinions of above, And I guess Tony24 might want to make sure whether 昨天我买三本书 could be used as a independent sentence. That was why I said should choose the other one. In general you should not simply say 昨天我买三本书。That sounds odd. If you choose that in the exam you'll get a cross?

[Tony24]

Got it guys! 

Thank you for your help ! :)

[Dawei3]

Publius - Thanks for the superb explanation.  Now I just need to remember where this was posted so I can read it again in the future.....