An upside down question mark is used in Spanish, it means the same thing as the regular one, but they use that one too.
Make sure your number lock key is on. The press and hold ALT, and type 0191.
you press the alt on the right side then on the number pad you press 0191 or you press alt+168 on the number pad on a mac you do shift and option and question mark at the same time (¿)
It is a query as to which end of you is up.
An inverted question mark is used in some languages, for example Spanish, to signify a question before it starts rather than solely at the end.
Draw it on your screen with sharpie