Was
What, object/thing
Wer
Who, person
Wo
Where, place where(static)
Wohin
Where, where to
Woher
Where from
Wie
How
Wie viel
How much
Wie viele
How many
Warum
Why
Wann
When
Welch_(er, es, e)
Which (the ending depends on gender of noun that follows)
Der Tag = welcher Tag
Das Buch = welches Buch
Die Farbe = welche Farbe