Sindarin is the language of the Sindar.

Sindarin developed in Beleriand after the rest of Eldar went to Eldamar, but because of the mutability of mortal lands it changed more swiftly than Quenya.

Although less lyrical than Quenya, Sindarin was still a gentle, beautiful tongue.

In Beleriand it was adopted for everyday use by the Exiles, especially after Thingol forbade the use of Quenya because it was the language of the Kinslayers.

Sindarin was adopted by the Edain (especially the Third House) and the DĂșnedain. Among these Men it was both a language of lore and a secondary common tongue.

Its use was forbidden in NĂșmenor during the days of its Shadow, but Sindarin survived to lend many words to Westron.
Encyclopedia entry originally written by tarkena