tests by nicks0206 with the online test builder (197 tests)
Ranked by: number of candidates
1. Pretérito indefinido: irregular (348347 candidates)
2. Verbos con diptongación (177468 candidates)
3. Soler + infinitive (157576 candidates)
4. Gustar, doler, encantar ... (157087 candidates)
5. El pretérito perfecto compuesto (136673 candidates)
6. Comparison : tan..como, tanto ..como, tanto/a/os/as..como (102945 candidates)
7. Imperfect (102847 candidates)
8. Adjectives agreement (100457 candidates)
9. Gerund (92065 candidates)
10. Present (80892 candidates)
11. Present (63992 candidates)
12. Animals (60252 candidates)
13. Conditional - SI + sequence of tenses (59136 candidates)
14. Pretérito Indefinido. Verbs in -ZAR, -CAR, -GAR (57410 candidates)
15. Colours (53705 candidates)
16. Do some shopping (49905 candidates)
17. Pretérito indefinido (46525 candidates)
18. VERBOS DE CAMBIO (45557 candidates)
19. What the weather like? (45047 candidates)
20. Pero .?.../...sino...? (43269 candidates)