| Term | Definition |
| dialect | Local or regional characteristics of a language. Has distinctive grammar and vocabulary. |
| Indo-European languages | Are spoken by about half the world's peoples. Includes English. |
| isogloss | A geographic boundary within which a particular linguistic feature occurs. |
| language | a systematic means of communicating ideas or feelings by the use of conventionalized signs, gestures, marks, or especially articulate vocal sounds. |
| language family | Languages that have a shared, but farily distant, origin. |
| language group | Consist of sets of individual languages. |
| language subfamily | The commonality of the languages is more definite. |
| linguistic diversification | How languages are different. |
| preliterate society | people who speak their language but do not write it. |
| standard language | The cariant of a language that a country's political and intellectual elite seek to promote as the norm for use in schools, government, the media, and other aspects of public life. |