tests by greg100 with the online test builder (215 tests)
Ranked by: number of candidates
1. Some / Any / Much / Many (207101 candidates)
2. Action and Stative Verbs (95755 candidates)
3. Used to / Be Used to / Get Used to (93498 candidates)
4. Past Simple / Past Perfect / Past Perfect Continuous (87674 candidates)
5. ' ing ' or ' ed ' (75451 candidates)
6. Sport : Play, Do, Go (75337 candidates)
7. Connectors (72626 candidates)
8. Daily Routines (64183 candidates)
9. Suffixes ( - ful or - less ) (56400 candidates)
10. Shopping and Vocabulary (54085 candidates)
11. Coordinating Conjunctions (53379 candidates)
12. Tell / Say / Speak / Talk (51944 candidates)
13. Had Better or Had Better Not (49748 candidates)
14. Too Much / Too Many / Enough (48558 candidates)
15. Present , Past or Future Passive (44174 candidates)
16. Few/Little/Less (42957 candidates)
17. Each Other or One Another (42753 candidates)
18. Borrow / Lend / Loan (42237 candidates)
19. After / Before / Ago / Since / For (41594 candidates)
20. Unreal Past (40376 candidates)