Translation:He does not work anymore due to the dirty fish.
I think there is no good explanation. In German we say exactly the same "Er arbeitet nicht mehr ....", or in Italian "(Egli) non lavora più ...", as well as in Spanish (Él no trabaja mas). In this sense, English is an exception. I guess that also in Danish this creates a slight ambiguity (not more - not anymore), but maybe somebody knows more?
In french, it is the same as english. We say "je ne travaille pas plus" or "je ne travaille plus". The first sentence means I could work more, but I can't because of the fish. The second just means I stop the work because of the fish. So the two sentences have different meanings. The first one, depending on the tone, you can say I am fed up with that fish, I could work more ! Or glad, the fish are dirty, I don't have to work more :) The second sentence is just about facts and there is no feelings in there. Depending on the context... Like always :) So I think, to translate from french or english, depending on the context, the sentences could be : - Jeg må ikke arbejde mere på grund af de beskidte fisk - Jeg skal ikke arbejde mere grundet de beskidte fisk What do you think ?
"Fishes" is not typically the plural of "fish" in English. If you were to use it in English conversation, it would sound a bit strange. I thought maybe it was an older word and equally acceptable, but Grammarist has an explanation:
... fishes has a few uses. In biology, for instance, fishes is used to refer to multiple species of fish.
I thought this was at least interesting.
It is not, but just like with the English 'fish', the plural of 'fisk' is 'fisk'. That means you'll have to look for clues in the sentence to see if 'fisk' is singular or plural. For example, in this sentence, it is 'de beskidte fisk' which means 'fisk' is plural because 'de' is a plural article, when it could also be 'den beskidte fisk' in which case it would be referring to a single fish.