verb object verb + time duration in different tenses
I study A for three hours.
I will study A for three hours
I studied A for three hours (no longer study it)
I have studied A for three hours (and still study it)
I want to study A for three years.

How do you negate all these?

Thanks!

Question

verb object verb + time duration in different tenses
I study A for three hours.
I will study A for three hours
I studied A for three hours (no longer study it) 
I have studied A for three hours (and still study it)
I want to study A for three years.

How do you negate all these?

Thanks!

Answer

I study A for three hours. 
translate :我用三小时学习A。
negate :我没有用三个小时学习A

I will study A for three hours 
ranslate :我将用三个小时去学习A。
negate :我以后不会去用三小时去学习A。

I studied A for three hours (no longer study it)
translate :我曾经用了三个小时来学习A，但我现在不再学习它了。
negate :我从来都没有用三小时来学习A。

I have studied A for three hours (and still study it)
translate :我现在依然用三个小时来学习A。
nagate :我现在没有用三小时来学习A了。

I want to study A for three years.
translate :我想要用三年来学习A。
nagate :我不想用三年来学习A。

Answer

For chinese...! 
I meant to say how do you translate these into chinese and then also negate them in chinese... Oops!!

Answer

Is this for Chinese, or English?