In English, you almost always make plurals with the letter "s".
Add it to the end of the word.
airplane = airplanes
lamp = lamps
toilet = toilets
beer = beers
Almost any word in English becomes plural with the simple addition of the letter "s" to the end of the word.
However, if a word ends with an "s", usually you need to do something different.
kiss = kisses
bus = buses
If it ends with a ch, or sh you do the same.
bush = bushes
wish = wishes
witch = witches
Words that end with "y" are usually done like this:
bunny = bunnies
mummy = mummies
If the "y" has a vowel in front of it:
monkey = monkeys
boy = boys
Now here are a few unusual plurals.
goose = geese
mouse = mice
deer = deer
sheep = sheep
moose = moose
There are more unusual plurals. IN GENERAL, you will form plurals by adding "s" or an "s" sound to the end of a noun.
However, the secret to plurals in spoken language is the sound of the "s".
If the word ends with a consonant like "t", "p", "k" (or a "c" with a "k" sound), "f"; you will pronounce the plural, like "s".
If the word ends with letters other than those mentioned above, in most cases, you don't want to pronounce a really sharp "s" sound. Instead you make it almost a "z" sound.
If you pronounce words like these with an "s" sound, you might actually be saying a different word.
The word "eyes" can sound like "ice".
eyes = eye(z)
So, in general it's pretty simple to form plurals in English, and when in doubt just placing an "s" sound at the end of the word indicates that you are speaking in the plural to most speakers of English.