How can I tell them apart

Ghana by any chance ?

How can I tell real ghana passport from a fake one

Seriously if you are in a "relationship" where you need to even consider this question there is something amiss.

How much cash have they asked you for ?

If its from Ghana... consider it fake... is there some reason you can't meet a REAL woman where you live? They do statistically outnumber men everywhere. And since polygamy is illegal in most of the developed world. Nobody has more than their fair share of women.