Might have not

navitasan1) He might have not been able to go there.2) He might not have been able to go there.Are both these sentences correct?Is there any difference in their meanings?

Not really. 'Might have not' is common in American English.

navitasanAre both these sentences correct?

In my opinion 1) is not correct, and 2) is correct.

navitasanI found some examples

The number of examples is not relevant. It's the number of examples of one version compared to the number of examples of the other version that you need. See this Google N-gram. You'll see that the

Anonymous navitasan1) He might have not been able to go there.2) He might not have been able to go there.Are both these sentences correct?Is there any difference in their meanings?Not really. 'Might have not' is common in American English.

Yes. Putting "not" last happens a lot in American English. It's also done with other words. This page
www.EnglishForw

Anonymous'Might have not' is common in American English.

Have you checked the N-gram link? You can change the language box to 'American English' specifically if you want, and the results are virtually the same. Even set at 'American English' there are comparatively zero uses of "it might have not been". Given that it's almost never used, I don't think saying