tests by felin with the online test builder (215 tests)
Ranked by: number of candidates
1. Much, many, little and few (373859 candidates)
2. Future continuous and future perfect. (237917 candidates)
3. I wish, if only (234273 candidates)
4. Adjectives - ing and ed (229355 candidates)
5. Adjectives and adverbs (194160 candidates)
6. Prefixes (1) (191341 candidates)
7. Although / in spite of / despite (175689 candidates)
8. Adverbs : Still, yet and already (166935 candidates)
9. Can, could and be able to. (112015 candidates)
10. Both / both of / neither / neither of / either / either (103158 candidates)
11. Is or are? (75544 candidates)
12. A, an, the, no article (74876 candidates)
13. Little, a little, few and a few. (74327 candidates)
14. As/Like (72221 candidates)
15. Modal verbs (70329 candidates)
16. Another, other or others (68412 candidates)
17. Demonstrative adjectives and pronouns (66173 candidates)
18. At the bank (65971 candidates)
19. Present perfect : continuous or simple (60871 candidates)
20. All / all of most / most of no / none of etc. (1) (58710 candidates)