"I cannot write articles."
Translation:Nie umiem pisać artykułów.
"ów" is only for genitive (or accusative) masculine personal plural,isn't it ? artykuł is masculine so why not artykuły ?
No, rather just for Genitive, but all kinds of masculine plural nouns, not only the personal ones. "artykuły" would be Accusative, like "Umiem pisać artykuły".
Not here. If you mentioned something more specific, even 'this article' (or 'these articles'), then it would be the right form and 'pisać' would feel wrong. Then it would be "I have this task but I don't have the knowledge/ability to complete it".
But here, you just have a general sentence about not knowing how to write articles. It's not specific.
I don't know whether I understood correctly, but I can answer this: I cannot write = Nie umiem pisać; I do not know how to write = Nie wiem jak pisać Basically the same in both languages, just translated more literally :)