Are you fascinated with words? Let’s unpack two wee ones:  may and can.   

“May” expresses possibility as in “You may be right.” It also communicates permission as in “May I have seconds?”  

“Can” addresses ability. (“She can type fast.”)  It also connotes permission as in “You may be excused.” When dealing with permission, either may or can is kosher.  "May” is also the name of a month, and “can” is an object that you can – or may – kick down the street. 

Which is correct?  (1) “If I may, can I ask you a question?” or (2) “If I can, may I ask you a question?”  Depending on the situation, both are proper.  

In closing …. 

“May the Lord bless you and take care of you; may the Lord be kind and gracious to you; may the Lord look on you with favor and give you peace.” (Numbers 6:24-26)