Put the verbs in brackets into the correct form and read the joke.

Mrs Jones ... (to get) dinner ready when her little son Tim came into the kitchen with a happy smile.

«What... you ... (to do) all the morning, Timmy?» his mother asked.

«Well, I... (to play) Postman», replied little Tim.

«But how could you play without letters?» wondered his mother.

«Oh, but I had letters. I ... (to look) in your old suitcase and found a pile of letters tied round with a ribbon. I posted one letter under every door in the street».