Conlang

A Conlang (short for "Constructed Language") is an artificial language that is created without regards to natural language formation. Whereas most spoken languages evolve over thousands of years, conlangs are created from scratch. (It should be noted, however, that some devoted conlangers attempt to make languages that appear to result from natural changes and indeed, very few actually go back and explore the changes that their language has supposedly undergone.)

There are numerous reasons for developing conlangs. Some linguists have created languages for use in place of natural languages (most notably, Esperanto). Some linguists create them for use in stories (for instance, Klingon). Some create them simply for pleasure or for educational purposes.

Planned, constructed, artificial
The terms "planned", "constructed", and "artificial" are used differently in some traditions. For example, few speakers of Interlingua consider their language artificial, since they assert that it has no invented content; its proponents prefer to describe its vocabulary and grammar as standardised rather than artificial or constructed.

Similarly, Latino sine Flexione (LsF) is a simplification of Latin from which the inflections have been removed. As with Interlingua, some prefer to describe its development as "planning" rather than "constructing".

Some speakers of Esperanto and Ido also avoid the term "artificial language" because they deny that there is anything "unnatural" about the use of their language in human communication.

By contrast, some philosophers have argued that all human languages are conventional or artificial.