Placement of 了 in a sentence using the "for x hours" structure

[adam2073]

Keep studying Chinese for 4 hours.

Yi4zhi1 xue2xi2__han4yu3__si4 ge4 xiao3shi2.

一直学习__ 汉语__ 四个小时。

 

In which blank does it go?

[anonymoose]

You don't need 了.

[H. Harroty]

Commonly, the first blank.

 

However, the second blank or no 了 at all just as 2# has said can also come up sometimes. To put 了 in the second blank is a kind of dialectical and quite rare speech, while to go without 了 has a slightly different meaning, which can, for example, mean "I will keep", or suggusts that another more important sentence is coming after it, so you omit 了 to de-emphasize this sentence.