I met two natives on an island - Benny and Lenny. They are either a knight, a liar or a knave. Knights always tell the truth, liars always lie and knaves alternate between truth and lie. They tell me this:
Benny : We are both of the same type.
Lenny : I am a knave.
Benny : Lenny is a liar.
A knight then tells me what Lenny is. From this I was able to work out what they were.