tests by laure95 with the online test builder (42 tests)
Ranked by: number of candidates
1. Could/Couldn't (306422 candidates)
2. Can/Must/Should (290661 candidates)
3. Can and can't (282293 candidates)
4. Must or mustn't (226266 candidates)
5. Like or would like (142258 candidates)
6. Should or shouldn't ? (122748 candidates)
7. Passive voice in past tense (121245 candidates)
8. Did, was or were (120991 candidates)
9. If clauses (105973 candidates)
10. Be allowed to (96156 candidates)
11. During, for or since (76109 candidates)
12. Present perfect or past perfect (67256 candidates)
13. Sentences : Like and would like (63574 candidates)
14. Infinitive proposition (43031 candidates)
15. Repeated comparative (38272 candidates)
16. Ago and past tense (34117 candidates)
17. Relative pronouns (31202 candidates)
18. This or these (26690 candidates)
19. Comparative (26037 candidates)
20. Questions and past tense (25087 candidates)