Free word-building in Interlingua
Words can be included in Interlingua in either of two ways: by establishing their internationality or by deriving them using Interlingua words and affixes. The second of these methods is often called free word-building.
Free derivation and compounding
While the national languages limit word-building by convention and usage, Interlingua has no such limits. Any derived word is admissible, as long as it is clear and useful.
Thus, in the Interlingua-English Dictionary (IED), Alexander Gode followed the principle that every word listed is accompanied by all of its clear compounds and derivatives, along with the word or words it is derived from. A reader skimming through the IED notices many entries followed by large groups of derived and compound words. A good example is the Interlingua word nation, which is followed by national, nationalismo, nationalista, nationalitate, nationalisar, international, internationalitate, and many other words.
Other words in the IED do not have derivatives listed. Gode saw these words as potential word families. Although all derived words in the IED are found in at least one control language, speakers may make free use of Interlingua roots and affixes. For example, jada (jade) can be used to form jadificar, (to jadify, make into jade, make look like jade), jadification, and so on. These word forms would be impermissible in English but would be good Interlingua.
Word-building by analogy
Gode and Hugh E. Blair explained in the Interlingua Grammar that the basic principle of practical word-building is analogical. If a pattern can be found in the existing international vocabulary, new words can be formed according to that pattern. A meaning of the suffix -ista is person who practices the art or science of…. This suffix allows the derivation of biologista from biologia, physicista from physica, and so on. An Interlingua speaker can freely form saxophonista from saxophone and radiographista from radiographia by following the same pattern.
Usefulness and clarity
As noted above, the only limits to free word-building in Interlingua are clarity and usefulness. These concepts are touched upon here:
Any number of words could be formed by stringing roots and affixes together, but some would be more useful than others. For example, the English word rainer means a person who rains, but most people would be surprised that it is included in English dictionaries. The corresponding Interlingua word pluviator is unlikely to appear in a dictionary because of its lack of utility. Interlingua, like any traditional language, could build up large numbers of these words, but this would be undesirable.
Gode stressed the principle of clarity in free word-building. As Gode noted, the noun marinero (mariner) can be formed from the adjective marin, because its meaning is clear. The noun marina meaning navy cannot be formed, because its meaning would not be clear from the adjective and suffix that gave rise to it.
A developing language
As the world's languages change, Interlingua changes with them. Each new Interlingua dictionary introduces words, and subsequent dictionaries include derivatives and compounds from those words. The developing vocabulary of Interlingua reflects its character as a living language, in practical use by a growing population of speakers.
- Brian C. Sexton, Karel Wilgenhoff, and F. Peter Gopsill. Supplementary Interlingua-English Dictionary. British Interlingua Society, Sheffield, 1991
- Gode, Alexander, and Hugh E. Blair. Interlingua: a grammar of the international language. Storm Publishers, New York, 1951
- Gode, Alexander, et al. Interlingua-English: a dictionary of the international language. Storm Publishers, New York, 1951