TEFL Question - Please help!

Hi, I’m completing an application for entry into a TEFL course. With the help of a couple of books to refresh my knowledge of basic grammar, I’ve managed to answer all but one question. Can someone please help me out with this one?

The sentence is, “I’ve played tennis a lot last year.”

Obviously the sentence is rewritten correctly as “I played tennis a lot last year” or “I played a lot of tennis last year.”

But it’s the second part to this question that I need help with – “Explain any rules that students would need to know.”

What “rules” would a student need to know to ensure they are able to correctly write such a sentence? I assume the answer has something to do with the use of “have” (I’ve) in the context of the first sentence.

Can someone please help me out with this? Thanks SO much!

The rule is:

The present perfect cannot be used with any adverbial which indicates a specific point in time in the past.

The adverbial in question is "last year" in your example.

Only adverbs of time which include the present (moment of speaking) can be used with the present perfect.

Example: I have answered five Forum questions today. ("today" includes the present moment, so it's OK.)
Example: I have answered five Forum questions yesterday. ("yesterday" does not include the present moment, so the sentence is incorrect.)