a fish => two fish

[keannu]

This might be a useless question, but why do you think the following nouns' plural forms are same as the singular forms in terms of same species?

ex)a fish => two fish
a deer => two deer

[SlickVic9000]

(Not a Teacher)

Because "fishes" and "deers" sound weird to native speakers?

[JMurray]

I believe many of these uninflected plurals, particularly those involving animals, survive from Old English… e.g. deer, fowl, fish, sheep etc. But "fishes", "fowls" and other examples are not uncommon in certain contexts.

not a teacher

[keannu]

I believe many of these uninflected plurals, particularly those involving animals, survive from Old English… e.g. deer, fowl, fish, sheep etc. But "fishes", "fowls" and other examples are not uncommon in certain contexts.

not a teacher

Do you happen to know why they used the same form both in plural and singular in old English?

[JMurray]

Do you happen to know why they used the same form both in plural and singular in old English?

Sorry Keannu, I'm getting a little out of my depth there but maybe one of the genuine teachers can shed some light on this.