Qui ne peut ne peut in French means "Who cannot, cannot" as the equivalent of the English saying "If you can't, you can't!"
Qui peut dire? in French means "Who can tell?" in English.
Qui, vous? in French means "Who, you?" in English.
Qui, moi? in French means "Who, me?" in English.
Qui conduit? in French means "Who is driving?" in English.
Qui est...? in French is "Who is...?" in English.
Translation: whoever wants [to do "x"] canThe brackets refer to information that would implied by a larger context.
Qui es-tu? in French means "Who are you?" in English.
Je suis qui? in French means "Who am I?" in English.
Qui ça? in French means "Who that?" literally and "Who are you talking about?" loosely in English.
Qui est de Paris? in French is "Who is from Paris?" in English.
C'est qui ton père? in French is "Who is your father?" in English.
Qui je suis, moi? in French means "Who am I?" in English.