Forming the plurals of nouns

There are some rules that help you form the plurals of nouns.

For masculine nouns:

- you add "и" if the noun ends in к, г, х, ч, ж, ш, щ:

жук  - жуки  (a beetle - beetles)

луч - лучи (a sunbeam - sunbeams)

- if it ends in "й" or "ь", you replace it with "и".

конь - кони (a horse - horses)

отель - отели (a hotel - hotels)

- for all the other nouns you add "ы":

телефон - телефоны (a telephone - telephones)

стол - столы (a table - tables)

For feminine nouns:

- you replace "а" with "и" if it's preceded by к, г, х, ч, ж, ш, щ:

книга - книги (a book - books)

ручка - ручки (a pen - pens)

- you replace "я"  or the soft sign with "и":

авария - аварии (an accident - accidents)

печь - печи (a stove - stoves)

- you replace "а" with "ы" for all the other feminine nouns:

почта - почты (a post office - post offices)

гостиница - гостиницы (a hotel - hotels)

For neuter nouns:

- you replace the last vowel ("o" or "e") with "a":

письмо - письма (a letter - letters)

полотенце - полотенца (a towel - towels)

- if a noun ends in "ие", you replace "е" with "я":

здание - здания (a building - buildings)

- there're some exceptions:

яблоко - яблоки (an apple - apples)

Please, note that some plurals are irregular:

мать - матери (a mother - mothers)

дочь - дочери (a daughter - daughters)

брат - братья (a brother - brothers)

ребенок - дети (a child - children)

человек - люди (a person - people)

Practice:  try the exercise.