Okay, let's add question tags to the sentences.
  - Jack isn't using the phone, is he?
 
  - Jerry won't go sightseeing with you, will he?
 
  - The boys are quarrelling, aren't they?
 
  - Tom is doing his homework, isn't he?
 
  - Tom must do his homework, mustn't he?
 
  - Sally can't help us, can she?
 
  - Tom can do his homework after lunch, can't he?
 
  - You haven't got any questions, have you?
 
  - Tom has got a CD player, hasn't he?
 
  - There isn't an atlas in the schoolbag, is there?
 
  - That's a new map, isn't it?
 
  - There's a new map in the atlas, isn't there?
 
  - It's got a new toy, hasn't it?
 
  - He wasn't late, was he?
 
  - There was a vase on the shelf, wasn't there?
 
  - There were three boys in the bus, weren't there?
 
  - Lena doesn't wear glasses, does she?
 
  - Lena isn't wearing glasses, is she?
 
  - Larisa speaks Italian, doesn't she?
 
  - Larisa is speaking Italian, isn't she?
 
  - The sheep sleeps here, doesn't it?
 
  - The sheep is hungry, isn't it?
 
  - Mr Smith often goes boating, doesn't he?
 
  - That's a bookshelf, isn't it?
 
  - There's a bookshelf above the desk, isn't there?