Exercise 21 - 30
Exercise 22 No 3
It's about used to.
Because the sentence is past time habbit
Adverb "tonight" indicate that it should be followed by verb in simple form after the word "would rather" is "stay" because it's present
Exercise 24 No 10
It's about Must/Should + perfective
After the subject is "he" should be followed by "must not have studied"
Exercise 25 No 1
It's about Modals+perfective
Because the if clause followed by past perfect is "had" and the main clause should be followed by "i would"
Ecercise 26 No 2
Its about adjectives and adverbs
Because the sentence is "an" and the noun is "novel" indicate that is should be followed by "intense" not "intensely"
Exercise 27 No 2
Its about linking copulative verbs
After the word "plays very" should be followed by the word "well" not "good"
Exercise 28 No 8
Its about comparisons.
Because the sentence can be followed by adjectives.
Exercise 29 No 5
Its about comparisons.
Because the word "so" indicate if its equal comparison. it should be followed by the word "as" after adjectives
Exercise 30 No 3
Its about comparisons.
Because the subject is "Pat's" it should be followed by "faster" not "fastest"