Understanding 了: difference between 她上个月去了北京 and 上个月我去台湾了?

Question

This grammar page tries to explain when to use 了 after a verb and when to use 了 after an object.

It claims when the time is specified, it's acceptable to use 了 after a verb and before the object as in 她上个月去了北京.

However, it provides another example where the time is specified yet 了 comes after the object (上个月我去台湾了).

1. When the time is specified, where does 了 go? After the verb or after the object?

2. How does the different 了 placement change the meaning/correctness of these two examples: (a) 上个月我去台湾了 and (b) 她上个月去了北京.

Answer 1

了 indicates 'completion of an action'

In "上个月我去了台湾" the action of "去" is completed, meaning you had gone there but it doesn't say you are still there or have already came back

In "上个月我去台湾了", '了' is a final particle for the emphasis (stress in tone) of the whole sentence

You can see the different by compare the two structure with other context:

• "下个月我去了台湾" is nonsensical, you can't already gone there when you say 'next month'

• '了' in "下个月我去台湾了" is a final particle for emphasis, and this sentence does make sense

Answer 2

Some linguist argue that 了 DO NOT indicates 'completion of an action'. Instead RVC ("Resultive verb complements") indicate 'completion of an action', but we are talking about 了...

了 renders either part or whole situation factual, that is real. Please, notice that factual situation does correlate (most of the time) with being in the past, but it could very well be in present or in future (see conditional factuality in ex.1)

1. If you do X, then It's all done. Part (If you do X) of the situation is real but the whole situation is "fake", that is it's a conditional statment. If condition X is factual, then Y will be done, but Y is not done yet (not factual yet).
2. I doing this thing now. Whole situation is factual.

There is not much difference in your example though:

(a) 上个月我去台湾了. Last month I have already gone to Taiwan. So my visiting Taiwan is a fact. Without (上个月) this sentence won't be translated with the past tense.

(b) 她上个月去了北京. Last month she had gone to Beijing, .... (looks like sentence hangs in the air, it's not complete, because you had said that A became fact before B, but you didn't provide B)

Answer 3

I have a slightly different theory to explain this conundrum. I don't think 了 directly acts as a "realis" particle to assert that something is factual; however, I think it tends to add such precision to the comment portion of a sentence that its use can help differentiate when a statement refers to reality or not.

In English, if I say: "I want to talk about your cousin getting a good job." You don't know the time frame of the job and whether the job is a past fact or maybe even just a hope for the future. However, if I say: "I want to talk about your cousin getting such a good job right after graduation last year after working so hard," you know I am referring to a past fact. If I say, "I want to talk about your cousin getting a good job as quickly as possible because the cousin has such potential and needs the money," you know I am referring to a future hope. By the rules of English, neither sentence actually makes any assertion about the factualness of the job, since a finite verb is not used to describe it. The two sentences simply refer to the status of the job with enough detail for you to work out whether or not the job is a fact or not. This is how I think Mandarin works and what 了 and other particles help to do.

When you say 她上个月去了北京, you are describing her trip to Beijing while specifically directing your listener to envision her as having completed the journey. This can sound incomplete if you do not immediately communicate why such precision about the stage of her trip is necessary in the discourse situation. If you follow up with a report on another event that took place after her arrival, probably while she was in Beijing itself, it will be clearer why you choose to be so specific and the sentence will be fine. Without an appropriate follow-up, it's as if the sentence only conveys: "I want to inform you about the aftermath of her arrival in Beijing." This is just a teaser that you want to say something else anchored in this time frame, but is not a good way to report on her trip as a whole. It sounds like an incomplete communication.

If all you want to do is report on the fact of her trip, you can just say 她上个月去北京了. This updates the listener about the trip without having to focus on her particular presence anywhere during the trip, which is not relevant to what you want to convey. You are just saying, last month she had a Beijing trip. Without 上个月, the timing of the trip becomes vague. Without 了, you are not updating the listener about the status of the situation, but naming some action, plan, habit, or idea relevant to the speech situation. Without any other words, it would be probably like saying: "I want to let you know about her Beijing trip(s)."

If you say 上个月我去台湾了, you do not tell your listener where to envision your location in the action, nor do you need to. You simply update your listener about your trip to Taiwan last month. Since this comment sounds like you are reporting a fact, it does assert a fact, even though there is no actual assertion morpheme in the sentence. I don't think you even actually assert that you reached Taiwan with this form of the sentence, although that would be have to be the assumption from such a simple sentence with no other very specific context. How can you inform someone of a trip to Taiwan last month without it having taking place, unless you go on immediately to do something like explain why it was only a tentative a plan that fell through or something similar?

Answer 4

了 means something YOU have done . YOU can say 我上个月去了北京 or 我上个月去北京了 NO DIFFERENCE .SAME MEANING ON PAPER WHEN SPEAKING , YOU CAN SAY HEAVILY ON 上个月 or 北京 TO EMPHASIZE 'TIME 'OR 'PLACE '

BUT YOU CAN NOT SAY 我下个月去了北京 or 我下个月去北京了❌

了 CANNOT BE USED IN FUTURE ( SOMETHING YOU HAVE NOT DONE )