- Everyone is frightened when they see a tiger. (wrong)
- Everyone is frightened when he sees a tiger. (correct)
- Explanation : 'Every' is a singular word, which when attached to a singular man like 'one' refers to all individual members of a group. So, it will take a singular pronoun.
- None of us have seen him. (wrong)
- None of us has seen him. (correct)
- Explanation : 'None' is a singular word, therefore it will take a singular verb.
- My books are better than my friend. (wrong)
- My books are better than those of my friend. (correct)
- Explanation : When comparing two things in a sentence, use 'that of', 'these of', 'those of'.