Inverted question mark
On Windows, hold Alt and type 0191 or 168 on the number pad, then let go of Alt.
Copy it
About the inverted question mark
In Spanish a question is marked at both ends, ¿ before and ? after, so a reader knows from the outset that the voice should rise. The upside-down mark was recommended in 1754, in the second edition of the Real Academia Española’s Ortografía, and it took approximately a century to become normal practice.