In Russian, an adjective must agree with the word that it describes in gender, case and number. In the nominative case, adjectives that describe feminine words usually end in -ая or -яя. Those that describe masculine words usually end in -ый, -ий or -ой. Those that describe neuter words usually end in -ое or -ее. Those that describe plural words usually end in -ые or -ие. The endings change depending on case.