Aspects of verbs: imperfective and perfective

So, you’ve learnt quite a few Polish verbs and are feeling very pleased with yourself – then, you find out that almost every English verb is equal to two Polish verbs! Yes, we’re talking about the two aspects – essentially, whether an action has been completed or not. So, for example with the verb robić (to do, to make):

• Imperfective is robić – “Wczoraj robiłem zadanie, kiedy przyszedł kolega.” (yesterday I was doing my homework, when my friend came round) – thus, the homework didn’t get done and the imperfective expresses an uncompleted, unfinished action (often translated as a progressive tense in English with -ing, for example 'was going', 'is going', "will be going")
• Perfective is zrobić – “Wczoraj wieczorem zrobiłem zadanie, a potem czytałem książkę.” (Yesterday evening I did my homework and then read a book. – ah! the homework is done so the perfective is a completed, finished action (often translated as a simple tense in English, for example 'went', 'go' 'will go').

For more on aspects, see page 269 of the excellent A Grammar of Contemporary Polish for a more in-depth explanation; also there is a very good discussion in Wikipedia about Aspects in Slavic languages, which draws mostly on the Polish example. However, and this is the point of this and the couple of postings following here: there are NO CLEAR RULES defining which prefixes form the perfective verbs – so you just have to learn the perfective version of the imperfective verbs parrot-fashion. However, it does help to know that perfective verbs are formed by:

1. adding a prefix
2. changing the stem suffix
3. a stem alternation and a change of the stem suffix
4. having two completely different stems (!)
5. verbs only having the imperfective form – no perfective, yaay...
   

If that looks complicated, then I’ve tried to simplify (a bit) by putting the above list into table form (in the posts immediately after this one) to print out and learn by self-testing – which is why there are three tables for each variant: one is complete for your reference, one is empty in the last column so you can test yourself on the meanings of the verbs, and one has an empty column for you to complete in order to learn the perfective forms. By the way, the forms are first and second persons singular and third person plural – if you can’t work the others out, let me know...