This Poster has fun images to help students remember what key question words mean, you can enlarge this at a staples/etc or give it to the students as a handout.
Por qué - the letter Y/ Why?
Dónde - a werewolf/ Where?
Cuándo - a venn diagram/ When? (venn/when)
Cómo - howling wolf/ How?
Quién - an owl/ Who?
Cuál - a witch/ Which?
Qué - a light bulb/ What? (watt*)