1. Preterite vs. Imperfect
Querer and Poder

2. Preterite Tense-QUERER
QUERER NO QUERER
tried refused
Ex. Yo quise dormir. Ex. Yo no quise estudiar.
I tried to sleep I refused to study.

3. Imperfect Tense-QUERER
QUERER NO QUERER
wanted did not want
used to want
Ex. Yo quería dormir Ex. Yo no quería estudiar.
I wanted to sleep. I didn’t want to study.

4. Preterite Tense-PODER
PODER NO PODER
managed to/succeeded failed
Ex. Yo pude dormir Ex. Yo no pude estudiar.
I managed to sleep I failed to sleep.

5. Imperfect Tense-PODER
PODER NO PODER
could/was able couldn’t/was not able
used to be able
Ex. Yo podía dormir Ex. Yo no podía estudiar.
I could/was able to sleep. I could not/was not able to sleep.

6. THE BOTTOM LINE!
The only way to say “wanted” or “not wanted” in the past, is using the IMPERFECT tense of querer.
Ex. She wanted to go home.
Ella quería ir en casa.

7. THE BOTTOM LINE!
The only way to say “could/was able to” or “was not able to” in the past, is using the IMPERFECT tense of poder.
Ex. She could not go home.
Ella no podía ir en casa.