tests by laure95 with the online test builder (42 tests)
Ranked by: number of candidates
1. Could/Couldn't (308115 candidates)
2. Can/Must/Should (293740 candidates)
3. Can and can't (284681 candidates)
4. Must or mustn't (228621 candidates)
5. Like or would like (142604 candidates)
6. Should or shouldn't ? (123835 candidates)
7. Passive voice in past tense (122968 candidates)
8. Did, was or were (122286 candidates)
9. If clauses (106616 candidates)
10. Be allowed to (96723 candidates)
11. During, for or since (76490 candidates)
12. Present perfect or past perfect (68047 candidates)
13. Sentences : Like and would like (63942 candidates)
14. Infinitive proposition (43714 candidates)
15. Repeated comparative (38835 candidates)
16. Ago and past tense (34311 candidates)
17. Relative pronouns (31801 candidates)
18. This or these (26799 candidates)
19. Comparative (26103 candidates)
20. Questions and past tense (25386 candidates)