In English, there are words whose plural form is performed not according to the rules – they simply need to be remembered. Let us look at them.
Man – Men
This pair can bring a lot of trouble to those who do not distinguish between the sounds e and æ. In many languages, such a small difference is really invisible, but you need to work hard on pronunciation so that your interlocutor correctly understands you.
There were many men in the mall.
Woman – Women
Everything is simple here – these two words are uttered in completely different ways, it remains only to learn their pronunciation.
Women are very sensitive to the lie or hypocrisy coming from other women, but they continue to believe hypocritical men.
Child – Children
Another exception that you just need to remember. Although, this word is met so many times in various places that it is impossible not to remember it.
Why are there so many children in the yard? – Because the first snow fell!
Person – People
Usually, beginners bypass the word person and in those cases when it is necessary to use this word they simply use man, for example, every man knows that.... People will understand you, but it is not accepted. There is a beautiful neutral word person for such cases. Which becomes such a close and popular word people in the plural.
Today is the day of carnival and therefore there are many people on the square.
Tooth – Teeth
We have come to exceptions related to parts of the body.
What beautiful teeth you have! – Thank you very much, but they are artificial.
Foot – Feet
Do not forget that foot is not only a part of the body but also a measure of length. This unit of measurement is used constantly in America. As it is easy to guess, it is equal to the length of the average foot, i.e. about 30 cm.
How good that you have such strong feet.
Mouse – Mice
A few more exceptions are animal names. We suspect a tricky question: what about computer mouse? Computer mice or computer mouses? Even native speakers have not come to the general opinion yet and dictionaries allow both forms.
How many mice did you see in the house? – About six.
Sheep – Sheep
If you count sheep at bedtime – be careful: one sheep, two sheep, three sheep.
Cannot sleep – count the sheep.
Fish – Fish and Sometimes Fishes
Another exception – this time from the water element. One fish, nine fish. As for the form of choice between fish and fishes, fish is for fish of the same species, fishes are for fish of different species. Note that this fact is not known to all native speakers, so be prepared that you will be corrected if you say While diving I noticed different fishes.
Today we caught a lot of fish, guys.
There are many more animals with a special plural formation, for example, deer – deer, goose – geese. However, it is unlikely that you regularly have conversations with foreigners about deer and geese – so let us leave the rest of the fauna for the dictionaries.
Words of Latin and Greek Origin
Of course, it is a sign of poor knowledge of the language to speak the above words in the wrong plural form. However, people will not expect from you, as not from the native speaker, the correct form of words coming from the Greek language and Latin. Many native speakers do not know even a third of these words-exceptions.
Fungus – Fungi
This is not about the mushroom itself, but about the whole kingdom of fungi – from lichens and yeast to fly agarics and truffles.
Today we studied fungi at the biology class.
Formula – Formulae
You can find the word formulas in a more informal environment, but there are only formulae in scientific papers on mathematics. The same can be said about a pair matrix – matrices.
Cactus – Cacti
There is also a “simpler” version along with the "right" one in this variant of the plural, as in many other cases –cactus – cactuses, etc.
We will not give a complete list of all the Greek-Latin exceptions, there are too many of them and a lot of exceptions even from exceptions.
You need to remember the necessary words, but you can always see the complex plural forms in the dictionary. Good luck in your study.