Difference between помнить and запомнить?

Question

What's the difference between помнить and запомнить?

Both are translated as "remember" in Google Translate.

[I know there's another question already on the difference between помнить and вспомнить. I understand those now.]

Many thanks!

Answer 1

They differ in aspect: помнить is imperfective (state), запомнить is perfective (state transition).

Запомнить is better translated as "memorize".

Я помнил / я запомнил roughly corresponds to English "I remembered (all along) / I've memorized (changed my state from non-remembering to remembering)".

As with other perfective / imperfective pairs, same ending puts the imperfective verb in present and the perfective one in future:

Я помню "I remember"

Я запомню "I'll memorize"

It's worth noting that those pairs are not necessarily the only ones possible. Запоминать is also an imperfective verb which could be paired with запомнить, it (again, roughly) corresponds to English continuous forms:

Я запоминал "I was memorizing"

Я запоминаю "I am memorizing"

Answer 2

за- used to make imperfective verbs perfective:

 помнить
     An act of remembering. I can handle the act, with no wait of results.

 запомнить
     I can handle the act that has/had been (shall be) finally completed (accomplished).

Most Russian verbs occur in pairs, one of the pair being an imperfective verb and the other a perfective verb. For perfective verbs a prepositional prefix про-, по-, раз-, за-, ... etc. is added.

As opposite to the OP, there is a perfective verb formed with the same prepositional prefix за-, wich means the start of some action:

  говорить         заговорить     
  to talk       to start talking

  играть           заиграть       
  to play        to begin to play

   петь            запеть         
  to sing       to start singing