tests by nicks0206 with the online test builder (197 tests)
Ranked by: number of candidates
1. Pretérito indefinido: irregular (344420 candidates)
2. Verbos con diptongación (175264 candidates)
3. Soler + infinitive (156127 candidates)
4. Gustar, doler, encantar ... (155458 candidates)
5. El pretérito perfecto compuesto (135924 candidates)
6. Comparison : tan..como, tanto ..como, tanto/a/os/as..como (102493 candidates)
7. Imperfect (102043 candidates)
8. Adjectives agreement (99320 candidates)
9. Gerund (91217 candidates)
10. Present (80067 candidates)
11. Present (63399 candidates)
12. Animals (59883 candidates)
13. Conditional - SI + sequence of tenses (58864 candidates)
14. Pretérito Indefinido. Verbs in -ZAR, -CAR, -GAR (56741 candidates)
15. Colours (53415 candidates)
16. Do some shopping (49731 candidates)
17. Pretérito indefinido (46234 candidates)
18. VERBOS DE CAMBIO (45284 candidates)
19. What the weather like? (44696 candidates)
20. Pero .?.../...sino...? (42877 candidates)