Glosa is a constructed international auxiliary language based on Interglossa (a previous draft of an auxiliary published in 1943). The first Glosa dictionary was published 1978. The name of the language comes from the Greek root glossa meaning tongue or language.

Glosa is an isolating language, which means that words never change form, and Glosa spelling is also completely regular and phonetic. As an isolating language, there are no inflections, so that words always remain in their dictionary form, no matter what function they have in the sentence. Consequently, grammatical functions, when not clear from the context, are taken over by a small number of operator words and by the use of word order (syntax). Being an a posteriori language, Glosa takes most of its vocabulary from Greek and Latin roots, seen by the authors as international in a sense by their usage in science.

History

Glosa is based on the draft auxiliary language Interglossa devised by the scientist Lancelot Hogben in the empty hours of fire-watching in Aberdeen during World War II. Interglossa was published in 1943 as a draft of an auxiliary.

Ron Clark came across the handbook of Interglossa: a draft of an auxiliary about 1960. Then he met Professor Hogben with the aim of developing the language. They worked to refine it, in order to make it more easily usable in all possible forms of communication. Wendy Ashby joined the project in 1972. When Hogben died in 1975, most changes had already been discussed. Hogben and Clark had agreed that the language should have a phonetic spelling (that is: each letter representing a single sound). This principle implied that the Greek CH, TH and PH now should be spelt K, T and F.

Finally a few further changes were introduced by Ron Clark and Wendy Ashby, who then gave the language the new name Glosa (from the Greek word for tongue, language – “glossa” being the English transliteration), and thus founded a new auxiliary language.

Until about 1979, Ashby and Clark tested the use of Glosa using local volunteers in the town in which they were living. During this period, the vocabulary and some details of sentence formation were developed and revised. They had moved to another town by the time they had published the first Glosa dictionary.

From 1987, the charity-status organisation GEO (Glosa Education Organisation) has promoted the teaching of Glosa as a second language in schools worldwide.

GEO's official website was set up by Paul O. Bartlett in 1996, and it is managed at present by Marcel Springer. It provides the Glosa Internet Dictionary (Glosa Inter-reti Diktionaria), as well as an introductory course, and other resources. A Wiki in Glosa was created in 2021.