tests by nicks0206 with the online test builder (197 tests)
Ranked by: number of candidates
1. Pretérito indefinido: irregular (340594 candidates)
2. Verbos con diptongación (174205 candidates)
3. Soler + infinitive (155202 candidates)
4. Gustar, doler, encantar ... (154641 candidates)
5. El pretérito perfecto compuesto (135545 candidates)
6. Comparison : tan..como, tanto ..como, tanto/a/os/as..como (102152 candidates)
7. Imperfect (101430 candidates)
8. Adjectives agreement (98907 candidates)
9. Gerund (90562 candidates)
10. Present (79816 candidates)
11. Present (63131 candidates)
12. Animals (59698 candidates)
13. Conditional - SI + sequence of tenses (58676 candidates)
14. Pretérito Indefinido. Verbs in -ZAR, -CAR, -GAR (56139 candidates)
15. Colours (53273 candidates)
16. Do some shopping (49496 candidates)
17. Pretérito indefinido (46030 candidates)
18. VERBOS DE CAMBIO (45038 candidates)
19. What the weather like? (44547 candidates)
20. Pero .?.../...sino...? (42574 candidates)