the serious perfective tense

1.(wrong) I can’t go with you because I broke my leg.
2.(correct) I can’t go with you because I have broken leg.

Why can’t I say like (1)? Is there grammatical mistake?

It should be “I can’t go with you because I have broken my leg.”

In the first example “you” broke your leg sometime in your life, the action is completed and there is no result that can be felt in the present.

In the second example (have broken) the present result of the action is more important than the past action: You have broken your leg and can’t walk and therefore you can’t accompany your friends.

Not quite so clear-cut as that, Gromit. #1 is certainly possible-- and much more common in AmE. While it places the fracture more solidly in the past, there is no reason why the fracture cannot affect the journey with friends. It is more a matter of the speaker’s perspective of each event than it is of any grammatical rule of tense.

(‘Have broke’ is of course wrong, Edison-- it should be ‘have broken’. I notice that you have been posting rather rapidly here; please take the time to ‘Preview’ and proofread your posts-- typing mistakes often make it difficult for others to decide precisely what you don’t understand about an utterance.)

I’m sorry for that, I’ll check them up clearly.

Thanks all, I’ve got it.