Edit

Gender

Russian nouns are either masculine, feminine, or neuter. You can usually identify a noun's gender by its ending:

Masculine nouns end in a consonant. Remember that й is a consonant.

Feminine nouns end in а or я.

Neuter nouns end in о or е.

Nouns ending in ь can be masculine or feminine. There's no rule, you just have to memorize the gender of these words.

Edit

Plural

Plural nouns can be treated as a fourth gender.

Masculine and feminine nouns generally add ы (if masculine) or change а to ы (if feminine). Those are called the "hard endings." Words with "soft endings" й (masculine), я (feminine), and ь (masculine or feminine) add и (if masculine) or change я to и (if feminine).

Neuter nouns change о to а ("hard ending"), and change е to я ("soft ending").

Edit

7-Letter Spelling Rule

However, г, ж, к, х, ч, ш, and щ, you use и, not ы. This 7-letter spelling rule also applies to adjectives. As a memory aid, ч, ш, and щ are together in the alphabet, and г, к, and х are pronounced at the back of the mouth.

Edit

Exceptional plurals

Some masculine nouns drop the last vowel before adding ы or и. E.g., подарок (present or gift) becomes подарки.

Some masculine nouns add a for plural. E.g., дом (house) becomes дома (houses).

Words of foreign origin ending in o, и, or у don't change between singular and plural. E.g., радио means "radio" or "radios." Note that foreign nouns with these endings also don't change in prepositional case (e.g., Colorado, Kentucky, and Peru).