Pretérito vs. imperfecto de saber, conocer, poder, tener que y querer:
| verbos | Imperfecto | pretérito |
| saber |
knew (was aware of) |
found out (became aware of) |
| conocer |
knew (was acquainted with) |
met (became acquainted with) |
| poder |
could (was able to, had the ability to) |
could (managed to, could and did) |
| tener que |
had to (was under or had the obligation) |
had to (was obligated to and did) |
| querer |
wanted to (had the desire to) |
wanted to and made the effort (tried) |
| no querer |
did not want to (had no desire to) |
did not want to (and refused to) |