tests by nicks0206 with the online test builder (197 tests)
Ranked by: number of candidates
1. Pretérito indefinido: irregular (343274 candidates)
2. Verbos con diptongación (174847 candidates)
3. Soler + infinitive (155896 candidates)
4. Gustar, doler, encantar ... (155262 candidates)
5. El pretérito perfecto compuesto (135858 candidates)
6. Comparison : tan..como, tanto ..como, tanto/a/os/as..como (102416 candidates)
7. Imperfect (101921 candidates)
8. Adjectives agreement (99208 candidates)
9. Gerund (90938 candidates)
10. Present (80003 candidates)
11. Present (63353 candidates)
12. Animals (59822 candidates)
13. Conditional - SI + sequence of tenses (58821 candidates)
14. Pretérito Indefinido. Verbs in -ZAR, -CAR, -GAR (56571 candidates)
15. Colours (53365 candidates)
16. Do some shopping (49707 candidates)
17. Pretérito indefinido (46185 candidates)
18. VERBOS DE CAMBIO (45160 candidates)
19. What the weather like? (44640 candidates)
20. Pero .?.../...sino...? (42756 candidates)