tests by nicks0206 with the online test builder (197 tests)
Ranked by: number of candidates
1. Pretérito indefinido: irregular (347051 candidates)
2. Verbos con diptongación (176456 candidates)
3. Soler + infinitive (156782 candidates)
4. Gustar, doler, encantar ... (156185 candidates)
5. El pretérito perfecto compuesto (136341 candidates)
6. Comparison : tan..como, tanto ..como, tanto/a/os/as..como (102770 candidates)
7. Imperfect (102607 candidates)
8. Adjectives agreement (100030 candidates)
9. Gerund (91612 candidates)
10. Present (80556 candidates)
11. Present (63715 candidates)
12. Animals (60184 candidates)
13. Conditional - SI + sequence of tenses (59061 candidates)
14. Pretérito Indefinido. Verbs in -ZAR, -CAR, -GAR (57214 candidates)
15. Colours (53653 candidates)
16. Do some shopping (49867 candidates)
17. Pretérito indefinido (46401 candidates)
18. VERBOS DE CAMBIO (45478 candidates)
19. What the weather like? (44985 candidates)
20. Pero .?.../...sino...? (43124 candidates)