It is wrong because it does not agree with ryba in gender. Ryba refers to fish in general (plural), so the plural form of small would be "małe".
No. In polish plural form of fish is "ryby". RYBA is always singular, so it has to be mała. If you wanted to say your small (plural) fish you say :
Wasze/Twoje małe ryby.
"wasza" is "your(s)" for plural 'you'.
"twoja" is "your(s)" for singular 'you'.
Both these versions are for feminine singular, as they describe a singular, feminine "fish".
Thank you, but if wasza is for plural, why is it marked as singular when you click on it?
Oh, that can be confusing, true. But that means, that "wasza" is used when the noun phrase is singular. There is one fish here, that belongs to two or more people (siblings, let's say). So I will say "wasza ryba" to John and Ann, because it is their fish.
If there were three fish (trzy ryby), I'd say "wasze ryby", as "wasze" is the form for "not masculine-personal plural" (plural for everything apart from 'groups of people with at least one man'). Or "twoje ryby", if I was only talking to John and all the fish were his.
Thank you very much, I understand now. So it is just marked a little irritating here