Prefixes (voorzetsels) change the meaning of a word. We do the same in Dutch:
legaal > illegaal
gewild > ongewild
regelmatig > onregelmatig
alfabeet > analfabeet
Slide 4 - Diapositive
Are there any rules?
Not really. You can only study prefixes by studying the words they belong to. Sometimes it is easy, because you already know a lot of them. Sometimes you have to look them up in a dictionary.
Slide 5 - Diapositive
Are there any rules?
There are minor rules for spelling though:
ir- is always followed by an r irresponsible
im- is always followed by an m or p immobile / impossible
a- is always followed by a consonant (medeklinker) apolitical