Noun endings are changed according to gender and nubmer.

~ In the nominative case plural endings of nouns are as following:

• for masculine: ы (и)
• for feminine: ы (и)
• for neuter: а (я)

~ After the consonants Г, К, Х, Ж, Ч, Ш, Щ we should write И

~ Following nouns also have ending "И" in plural form of the nominative case:

• masculine nouns with ending "й"
• feminine nouns with ending "я"
• all nouns with ending "ь"

~ Some masculine nouns with hard consonant or "ь" at the end have "a" ("я") ending in plural form of the nominative case.

Examples:
дом (the house) => дома
учитель (the teacher) => учителя
поезд (the train) => поезда
город (the city) => города
цвет (the color) => цвета

maskulin:
студент (der Student) => студенты
мальчик (der Junge) => мальчики
камень (der Stein) => камни


feminin:
лампа (die Lampe) => лампы
девочка (das Mädchen) => девочки
кровать (das Bett) => кровати


neutrum:
окно (das Fenster) => окна
поле (das Feld) => поля


~ Г : книга (das Buch) => книги

~ К : знак (das Zeichen) => знаки

~ Х : эпоха (die Epoche) => эпохи

~ Ж : нож (das Messer) => ножи

~ Ч : врач (der Arzt) => врачи

~ Ш : карандаш (der Stift) => карандаши

~ Щ : товарищ (der Genosse) => товарищи