"My friend was in New York yesterday."
No, it would sound strange. 昨天 makes it clear that this event has already occurred. Don't think of 了 as an automatic past tense marker like English verb + -ed.
Okay. I am trying to understand this one, so please bear with me.
So we don't use 了when the date is clear right? Then why does this question use 了 , "他们上个周末见了孩子。"(1) Is it because 见(2) is a verb while 在(3) can be considered a verb clause, adverb, or even a preposition? Even then though, depending on how we use 在 wouldn't it still obey laws that all verbs/verb clauses do unless specified?
It would be a contradiction in the case of the thread question, right? Thus, you would have to rely on the context given by the date? I've looked it up a little and I found a forum(4) talking about how it is right in a technical manner, but it isn't right idiomatically. If you're in the states is it like using y'all? I'm really looking forward to your answer because I think I am overcomplicating a likely simple concept.
1:https://forum.duolingo.com/comment/25310332 2:https://resources.allsetlearning.com/chinese/grammar/%E8%A7%81 3:https://resources.allsetlearning.com/chinese/grammar/%E5%9C%A8 4:https://forum.wordreference.com/threads/verb-%E5%9C%A8%E4%BA%86.2693622/
Nevermind, found the solution to my problem (hopefully). They talk about the usage of 了and 在 this thread:
In which Eanorel2 gives a ton of information and then a Chinese StackExchange link as follows:
So to summarize from the Chinese StackExchange ,"了 does not mean past tense. It denotes CHANGE."
Do you say "what did you made last week?"? 了 and 昨天 in the same sentence would look like that
This would be so much better if the app would actually teach us instead of trial and error, and error, and error and....
The languages with alphabets differents from romanian alphabet always looks strange as that cuz duolingo has only 2 spots for text input
I wish that Duolingo would put translated words next to each character in the answer sentence, as they do for French.
Why is 了 not used with 在?
I think of it this way: I don't say, "I was atted New York yesterday." In Chinese "to be" verbs remain the same regardless of the time frame. 在 is a verb that includes "to be"in its meaning along with "at." So I literally say with 在, "Today I am at; tomorrow I am at; and yesterday I am at."
Only in some cases(like really close relationships as brothers, sisters, mothers and fathers)
no it can include friends depending on the degree of closeness. As long as its someone who's more than just an acquaintance it is accepted
In Chinese, the time has to go directly before or after the subject (beginning of the sentence).
because the zuotian implies already that the event happened already, you don't need to have the past particle. Just like how you wouldn't say "I ate before this already"; you'd only say "i ate before this"