tests by juldan with the online test builder
(10 tests)
Ranked by: number of candidates
1. To Go To Come (6858 candidates) 
2. Doler (5806 candidates)
3. Difficult agreement (4214 candidates) 
4. Ser/estar with the same adjective (3568 candidates)
5. Object personal pronoun (2651 candidates)
6. Calling someone (2359 candidates)
7. Add accents (2288 candidates)
8. Idioms: consequences (1376 candidates)
9. Add accents (1093 candidates)
10. Accents (1003 candidates)
(10 tests) Ranked by: number of candidates
1.
To Go To Come (6858 candidates) 2.
Doler (5806 candidates) 3.
Difficult agreement (4214 candidates) 4.
Ser/estar with the same adjective (3568 candidates) 5.
Object personal pronoun (2651 candidates) 6.
Calling someone (2359 candidates) 7.
Add accents (2288 candidates) 8.
Idioms: consequences (1376 candidates) 9.
Add accents (1093 candidates) 10.
Accents (1003 candidates) 