You have a friend who is learning Arabic. You ask: (how long/learn/Arabic?)
How long have you been learning Arabic?
Some friends of yours are having a party next week. You ask: (how many peolple/invite?)
How many people have you invited?
You have just arrived to meet a friend. She is waiting for you. You ask: (wait/long?)
How long have you been waiting?
A friend of yours is saving money to go on a world trip. You ask: (how much money/save)?
How much money have you saved?
A friend of yours is saving money to go on a world trip. You ask: (how long/save?)
How long have you been saving money?
You see somebody fishing by the river. You ask: (catch/any fish?)
Have you caught any fish?
A friend of your is a teacher. You ask: (how long/teach?)
How long have you been teaching?
A friend of yours is a writer. You ask: (How long/write/books?)
How long have you been writing books?
A friend of yours is a writer. You ask: (how many books/write)
How many books have you written?