'may I enter', or 'may I enter in' should be acceptable
"May i come in mama?"... is wrong?
May l come in, mother? Is wrong?.
what is the answer for this question? is "karibuni" right?
Karibuni would be for more than one person. In this case you'd say karibu.
Much as I deplore the dumbing down of English, it is a fact that "Can I....?" is now an acceptable alternative in English to "May I...?", unfortunately to the point that even I use them equally <shame-face>
The dumbing down of English began when we stopped marking gender and case on our articles ...
"May I enter," or "May I enter in" are common English phrases and should be acceptable