What: nani or nan
Where: doko
Where to: doko ni
Where at: doko de
Why: doushite or naze
Who: dare or donata
With whom: dare to
To whom [did you give something]: dare ni
Which: dore
Which (particular object): dono (object)
What kind of: donna
How (by what means, as in travelling): nan de
How (used to propose something, like "how about X?"): ikaga
How much [does something cost]: ikura
How many (also used for asking a person's age): ikutsu
How long will something take: donogurai
When (time in general): itsu
What time (specific hour): nanji
What day (of the week): nan-youbi
What day (of the month), or what date: nan-nichi
What month: nangatsu
How manu months: nan-kagetsu
What year: nan-nen
How many people: nan-nin
How many animals: nanbiki
What floor (of a building): nangai