tests by viothur with the online test builder
(9 tests)
Ranked by: number of candidates
1. Pretérito indefinido (800279 candidates) 
2. Subjunctive: present (37206 candidates)
3. Pretérito indefinido, pretérito perfecto. (28659 candidates) 
4. Irregular: hacer, haber, ir (6246 candidates)
5. Ser / estar (5644 candidates)
6. Por / para (4383 candidates)
7. Haber de / Tener que (1678 candidates)
8. Gift (1521 candidates)
(9 tests) Ranked by: number of candidates
1.
Pretérito indefinido (800279 candidates) 2.
Subjunctive: present (37206 candidates) 3.
Pretérito indefinido, pretérito perfecto. (28659 candidates) 4.
Irregular: hacer, haber, ir (6246 candidates) 5.
Ser / estar (5644 candidates) 6.
Por / para (4383 candidates) 7.
Haber de / Tener que (1678 candidates) 8.
Gift (1521 candidates) 