This guest post is by Alice Sudlow. Alice is a professional editor who works on our team here at The Write Practice. She has a deep love for young adult novels and a talent for scouring dirty countertops and comma-spliced prose.

English is a pretty convoluted language. Even when things seem straightforward, exceptions pop up to turn regular rules upside down.

Here’s a question for you: what’s the plural of “fish”?

How to Write the Plural of Fish

Normal Pluralization

In general, English pluralization rules are pretty simple: just add an “s.”

My friends and I walked our dogs to the pond, where we saw a few turtles and many fish.

Friend, dog, and turtle all become friends, dogs, and turtles.

And then there’s fish.

The Plural of Fish

One fish is just that—a fish. One scaly animal swimming in the sea (or river, or pond, or fishbowl).

Here’s the thing: if you have two scaly animals swimming in your fishbowl, you have two fish. No matter how many fish you have, the word “fish” doesn’t change.

This isn’t the only case in the English language where the singular and plural forms are the same word. The plural of moose, for example, is moose. The plural of deer is deer. The plural of sheep is sheep.

Why, then, do we sometimes hear the word “fishes”?

Fish vs. Fishes

Unlike “sheeps” or “mooses,” the word “fishes” is a real, grammatically correct English word. It doesn’t generally come into play in regular conversation, but it’s a helpful term in biology.

Remember that example from above of the fish in the pond? In general, we’d say we saw fish.

Maybe, though, we saw multiple species of fish. There were some bass, and some carp, and some minnows. In this case, we could say we saw fishes.

Fishes: Plural vs. Possessive

There’s one more reason you might hear the word “fishes” tossed around: when it’s used in the possessive form.

To indicate one fish has something, we add an “’s” to the end. For example:

I have one goldfish in a bowl. My fish’s eyes are big.

To indicate that multiple fish have something, though, we have to pull out the “fishes” again:

Sarah has three goldfish in a bowl. Her fishes’ eyes are even bigger.

In this case, we use “fishes’” no matter how many species there are.

Fishy Rules of Pluralization

Throughout the history of the English language, we’ve pulled in words from all kinds of different sources and integrated them into regular language. For the most part, we’ve been okay about standardizing things—generally, to make something plural, all you have to do is add an “s” to the end.

Sometimes, though, we mix it up with convoluted exceptions, and then we end up with “moose,” “sheep,” and . . . “fishes.”

What can I say? English grammar is a fishy business.

Have “fish” and “fishes” ever tripped you up? What other convoluted English grammar irregularities do you find interesting? Let me know in the comments.


Two characters are going scuba diving. One is familiar with the correct use of “fish” vs. “fishes,” and the other has never seen a fish in their life. Write their story for fifteen minutes. When you’re done, share your writing in the comments, and remember to leave feedback for your fellow writers!

Alice Sudlow
Alice Sudlow
Alice Sudlow has a keen eye for comma splices, misplaced hyphens, and well-turned sentences, which she puts to good use as the content editor of The Write Practice and Short Fiction Break literary magazine. She loves to help writers hone their craft and take their writing from good to excellent.