Poder in preterit vs. imperfect

Question

When using poder in the imperfect, it means could, to be able to. When using poder in the preterit, the meaning changes to succeeded. Is there a good way to keep them separate? My students keep confusing the two meanings.

Answer 1

Example:

You are swimming to an island.

If you drown on the way there because you can't swim that far, you would say "No pude hacerlo."

If you make it to the island, you could say "Pude hacerlo."

However, if you had made the trip once already and know you COULD do it (Podía hacerlo), but got eaten by a shark and failed to make it to the island: "Yo podía hacerlo pero no pude."

Or just break it down like this: "podía" was having the ability to do it in general. "Pude" is whether or not I did it "that one time".

Also, as was mentioned, there are other "meaning changing" verbs, which don't REALLY "change" meaning at all.. you just stop viewing the action as a state (imperfect: wiggly line or waving hand ) and view it as a specific event OR beginning/end (preterite: a star shape or hand burst) of the state. The verb won't ALWAYS translate like that, and that's important too, but you can use this as a starting point.

Yo supe....... y yo sabía. :: I found out (start of action, one time event) and then I knew.... (state)

Yo conocí ... y yo conocía :: I met (start of action, one time event) and I then knew (state)

Yo pude .... y yo podía. :: I succeeded (start of action, one time event) and then I could do it... (state)

Yo quería .... y yo quise :: I wanted to (state) .... and then I [finally] tried to (end of state, one time event)

Yo tuve .... y yo tenía :: I got (start of action, one time event) and I then had (state)

Answer 2

Yes, this is a tough one.

If you teach your students that the preterite answers the question "what happened" and the imperfect gives more background information (specifically: something was going on, always went on, used to go on - or - just the way things were), I believe you will eliminate the confusion.

This will help with all of the verbs that change meaning in the preterite - querer, saber, poder, etc.

In this specific case: "Pude llegar a tiempo" - I managed to arrive on time - meaning that in spite of obstacles or poor timing or whatever, I managed to get there.

Examples with querer and saber: "Quise levantar las pesas pero no pude" - I tried to lift the weights but I couldn't (I didn't manage to, I wasn't successful). "¿Cuándo lo supiste?" - when did you find out about it?
All of those sentences answer the question "what happened".

I have found that many, many examples and a lot of repetition, and then leaving the grammatical point alone for couple of days and returning to it later are very helpful techniques.

Answer 3

Succeeding is a specific action whereas having an ability is not. This is in agreement with the usual distinction between the two.

The only way to know if you have the ability is to attempt and succeed. Past performance is not an infallabible guide to present ability. - samdie, Jan 15, 2010