Ex 1: /g/: green, game, garden, get, group
/k/: colour, school, kitchen, chemistry, chemical, culture, cold, classroom, sick, clotjes, call, communication, traffic, cancel, clean
Ex 2: 1, Have you ever met/ sat
2, did you start/ had recently completed/ asked
3, saw/ have already seen
4, has worked
Ex 3: 1, was having
2, has traveled
3, hasn't begun
4, is running
5, invited/ didn't come
6, has cleaned
7, began
8, has made
9, is cooking
10, going
11, haven't seen/ left
12, is/ playing
13, left
14, has been
Ex 4: 1, a
2, e
3, g
4, n
5, h
6, c
7, f