Irregular plural nouns | the MUTANT PLURALS | Grammar | Khan Academy

Hello Garans! Welcome to irregular plurals part four: the mutant plurals.

Ooh, yes, friends! These words have mutant superpowers, uh, in that they can transform weirdly and obnoxiously, not obeying any other rules of English pluralization. But here's the cool thing: there are only seven words that behave this way.

What way? I'll explain by writing all of them down. The words are foot, woman, man, tooth, goose, mouse, louse. Looks pretty straightforward, right? Uh, the thing about these words is that none of them take S as a plural.

So, the plural of foot is not foots. The plural of woman is not women's. The plural of tooth is not tooths. The reason these are called mutant plurals is because the vowel sound—the o or the o or the a or the o or the o or the ow or the ow—turns into a different sound, turns into a different vowel sound.

So, the plural of foot is not foots but feet. The plural of woman is not woman's but women. The plural of man is not man's but men. The plural of tooth is not tooths but teeth. The plural of goose is not gooses but geese. The plural of mouse is not mouses but mice. And the plural of louse is not louses but lice.

You can see that mouse and louse actually change their end spelling as well, uh, to from SE to CE, even though it's the same sound: lice. For whatever reason, just from some quirk of our spelling history, not only do we change the vowels used here, we also change the consonants.

You see why is this the case? I'm so glad you asked! I'm going to save that for another video. In the meantime, just these seven words—1, 2, 3, 4, 5, 6, 7—are the only words in English that behave this way.

So, you're in luck! This is a handful of words to memorize and, provided you're not borrowing anyone else's hats, ideally you won't have to worry about lice very often. That's my hope!

You can learn anything.
Daveid out.