I have asked him a lot of question.
I have asked him lots of question.
Are the both sentences correct?
Actually I want to learn can I use a singular noun after "a lot of" or "lots of".
You can use lot with both countable and uncountable nouns.
Eg: I've a lot of money.
When using "a lot of" or "lots of" (which I think to be less formal) + countable noun, it should be plural. ------ questions.