1. They are learning English now. Are they learning English now? They aren't learning English now.
2.Is making. Is the girl making a cake now? The girl isn't making a cake now.
3. am reading. Are you reading another book on history now? I'm not reading another book on history now.
4.were eating. Were you eating lunch in the park at 12:30 yesterday? We weren't aeting lunch in the park at 12:30 yesterday.
5.was jogging. Were you jogging through the park yesterday morning? I wasn't jogging through the park yesterday morning.
6.was playing, were listening. Was the child playing the piano while his classmates were listening to him? The child wasn't playing the piano while his classmates weren't listening to him.
7.are losing,
8.was working, were dancing
9.were you thinking about
10.will be happening
11.decorates
12.hurt, was working
13. will be reading
14.will you be doing, will be cooking
15.does your mother read, reads, is reading
16.cooks, has cooked
17.have, am having
18. is Bob doing, is tasting