Are these sentences grammatically correct?

I always heard you saying that word.

I have always heard you saying that word.

Question

Are these sentences grammatically correct?

I always heard you saying that word.

I  have always heard you saying that word.

Answer

Both work. However, the second is more clear (at least to a native speaker :)

Answer

I would suggest "... say that word" rather than "..saying that word".  Say is past tense, just like heard.