Tongues

The common tongue is Westron, everyone speaks Westron by default when talking.

Different races have their own specific tongues:

Dunlendings speak Dunael
Dunedain    speak Adunaic
Eorlings    speak Rohirric
Edain       speak only Westron
Hobbits     speak only Westron
Dwarves     speak Khuzdul
Silvan      speak Silvan
Sindar      speak Sindarin

Haradrim    speak Haradaic
Numenoreans speak Adunaic
Easterlings speak Easterling
Uruk-hai    speak Orcish
Variags     speak Variag

There are also special tongues which different species speak. Black Speech is spoken by top servants of Sauron. Orcish is not a language of itself, but is the term applied to the many tongues of the orcs. Since the language varies from tribe to tribe, no one, not even the orcs themselves, can know orcish 100%. Certain races of man who trace their ancestry to the far east may also speak easterling.

See also:    speak,  languages