When is it correct to not use the irregular form for a plural? e.g. mouses vs. mice

Question

I seem to recall that an English teacher somewhere along the course of my education had indicated that when referencing distinct types of a word, e.g. a computer mouse and the mammal, it would be proper to refer to them as "two mouses" rather than mice.

Is that actually the case? If so, where are the lines commonly drawn - consider for example observing a Canada Goose and a Greylag Goose as a more gray area or perhaps the tooth from a mouth versus a tooth from a saw blade as something quite distinct.

Answer 1

I don't know if there are hard and fast rules about this. With mouse it seems to be that the accepted plural is mice, but if you're talking about a computer mouse you can use mouses or mice, so you'd be safe if you always used mice

Merriam Webster:

plural also mous·es : a small mobile manual device that controls movement of the cursor and selection of functions on a computer display

Oxford English

2 (plural mice or mouses)a small handheld device which is moved across a mat or flat surface to move the cursor on a computer screen.

As far as geese are concerned, I had thought they were always geese, but apparently there's also:

3 (plural gooses) a tailor's smoothing iron.

But the plural of tooth is always teeth!

Answer 2

The Language Instinct by Steven Pinker offers an explanation involving Walkman/Walkmans and fly out/flied out (baseball terminology), which basically says that a Walkman is not a type of man, thus it does not follow the irregular plural rules for man. Similarly, fly refers to a "fly ball", which is not a verb, so the irregular verb rules for "fly" the verb do not apply to "flied out". The full explanation is in chapter 5, titled "Words, Words, Words".

Mice versus mouses is debatable. Most people I know say "mice", and indeed it could be argued that a computer mouse is a form of mouse, as it somewhat resembles one (albeit upside down), and was named after the rodent.

Answer 3

The example my teacher used is fish, where the regular plural is used for multiple varieties: a meal of salmon, trout, and cod would contain three fishes, but not necessarily three fish.

It would strike me as rather strange to extend that to mice or geese, though. I suspect this is an exception rather than a rule.

Answer 4

I think that in this case, where you're speaking of the word itself rather than its referent (mention rather than use), you might just put the word in quotes and avoid the issue that way:

There are two "mouse"s in English: one is an annoying little thing that never holds still when you want it to, and the other is a rodent.

Answer 5

When a word has come independent enough from its origin, it might evolve on its own.

Besides mouse, computers are full of words that are borrowed from somewhere else, like bus, gate, board, card, screen, fire wall, chip, port, package, to mention some. Most have become quite independent from their origins, but you don't notice that because their plural forms remain the same.

Answer 6

There is no rule about this. But about mouse if you're using the word as an animal or a quiet nervous person the plural will be Mouse and if you're using it as an digital device the plural will be mouses (rather than mice).