"A cápa a halak mögött úszik."

Translation: The shark is swimming behind the fish.

[Krisbaudi]

Is it not allowed in English to use the word fishes for the plural (halak).

[mizinamo]

Generally, fishes is used only when you are talking about different types or species of fish.

The usual plural for fish is simply fish. (Like with sheep and deer and perhaps a handful of others.)

[Krisbaudi]

Ohhh I didn't know that. Thank you very much!