Both are correct. This is true, even in BrE, though the latter may be preferred.Also, which tense would students use to say they couldn't/didn't
want todo their homework when asked by their teacher to show their assignments?
'Sorry, sir, I didn't do / haven't done my homework'
(I suspect both are possible, the former preferred by American speakers)
It certainly isn't used in BrE.Finally, as in the above sentence, the word 'teacher' used vocatively would be wrong, wouldn't it?