Would ''Er du klar?'' work as well?
That would be "Are you ready" or "Are you clear"
No that doesn't work. 'Er du klar?' = 'are you ready?'
Just a heads up though, in some dialects, like my own, 'klar' means both 'tired' and 'ready'. But that's nothing to worry about until you start speaking with people.
Jeg er ferdig med å lese boka. = I am done reading the book.
Jeg var ferdig med å skrive brevet. = I was done writing the letter.
Er dette riktige?