using 了 with duration time phrases.

[meowypurr]

I know there are lots of threads about 了 already, but although I found useful and enlightening information, I still have some specific unanswered questions. I already know about the basic differences between verb-了 and sentence-了, but I'm confused about using 了 when a duration of time is involved.

Here are some example sentences. What is the difference between all of these sentences, in regards to translation/usage? I'm not even sure if all of them are correct, and if not, is there a different verb I could use to make it correct, or does the construction not exist at all?

１，我学中文学了三年了

２，我学中文学三年了

３，我学中文学了三年

４，我学中文学三年

５，我学三年中文

Thanks.

[HashiriKata]

１，我学中文学了三年了: OK : I've been studying Chinese for 3 years (and continuing)

２，我学中文学三年了 : I personally would not say this, and say instead either no 1 or no.3, depending on what I mean to say.

３，我学中文学了三年: OK: I (have) learned Chinese for 3 years (with this type of sentence, you're probably going to say something else after it.)

４，我学中文学三年: Not OK: Understandable but native speakers would not say this.

５，我学三年中文 : Not OK: Sounds like something missing. I would add 了 either after the verb or at the end of the sentence.

[meowypurr]

thanks~