Տեսություն

Explanation
In English, there are nouns that don’t follow the standard rules for pluralization. There are no easy ways to remember them, so they generally have to be memorized.
Most singular nouns form the plural by adding -s.
     a sandwich - sandwiches
     a rose - roses
There are also irregular noun plurals. The most common ones are listed in the table below.
                                                          
man - menfoot - feetmouse - mice
woman -womentooth - teethlouce - lice
child - childrengoose - geeseox - oxen
                                                   
There are nouns that are used only in the singular (furniture, homework).
There are nouns that are used only in the plural (jeans, trousers, clothes, people).
There are also nouns that are used both in the singular and in the plural (sheep, deer).
 
Add -es  to nouns ending in ch, sh, ss, z, x, o  to make them plural
Drop the  -f  and -fe  at the end of the nouns and add  -ves  to make them plural
Drop the -y  and add  -es  to the nouns ending with a  consonant  and y, change  -y to -ies