SIL Encore IPA fonts - including SIL Doulos IPA 93 - are downloadable from this site.)
To raise the question of a vocabulary for LangX is first to ask what an IAL is for. The answer, of course, is to communicate internationally. As a consequence, an IAL must differ fundamentally from those languages or dialects which may appear to exist only to reinforce circumscribed cultures, and identify or exclude outsiders through the operation of shibboleths, irregular orthography and grammatical minefields. The rule of law in the realms of grammar, orthography and vocabulary is therefore as essential to an IAL as the principle of economy, but should not require a lowest common denominator approach that also restricts the scope of dialogue. The ideal solution is itself a dilemma: a linguistic continuum or hierarchy, embracing words of varying semantic and phonological difficulty, and allowing users to select their level of discourse. Hence, they might choose one-clause utterances containing only words with the easiest and commonest international speech sounds, or at the other extreme, complex sentences interweaving words transliterated from any tongue, living or dead, organic or constructed, commensurate only with the linguistic capacity of LangX's grammar and orthography, and of the participants in the discussion.
Since the memorising of words is the most difficult and time-consuming aspect of learning a language, vocabulary-design is the weightiest part of creating one, though possibly the least onerous. Moreover, it is a task well beyond the individual author, so at this stage it would be invidious to place any restriction upon vocabulary - with the exception of words with phonetic qualities that cannot be denoted by a limited 53-phoneme spelling system.
Neologism, which requires a sense of euphony as well as an understanding of etymology, is a difficult art best practiced by the artless. Even its geniuses - Bullokar, Shakespeare etc. - coined many failures. In the modern age neologism has become universal in more ways than one, through the globalisation of religion, science, literacy, culture and brand names. Quite often, new words and names are accepted into many tongues, varying only in accordance with the scripts and orthographies in which they appear. In such cases it should be possible to identify the word in its original or optimal form, for use in the IAL.
The notion that the IAL's lexicon of common words should contain the most generally acceptable phonemes, rather than consonant clusters and other speech sounds that some of the world's peoples find particularly difficult, found confirmation in UPSID: the phonological inventory of 317 languages published in 1984 by researchers at the University of California. Examination of the selected tongues, each one representative of a different recognised language family grouping, showed the following 20 to be the commonest consonant phonemes:
Most languages have 14 - 16 of these phonemes (the West African language Bambara is closest to the exact complement - it lacks [?] but has [z] and [dZ]). So this table is a useful guide to the consonant phonemes the commonest words of LangX might contain. Similarly, some vowels are more universal than others, and these are the ones that should tend to feature in common words.
Synonyms and near-synonyms present difficulties in most languages - how much more in an IAL which, initially admitting all words from all sources, would be inundated by hundreds or thousands of synonyms and near-synonyms - not to mention umpteen million words! Happily the problem is much less daunting than it might appear at first sight, due to a number of mitigating factors, including the following:
(1) When most words from most languages can be rendered into the same orthography, most of the world's words will become available to the discriminating speaker or writer, who will then be able to choose the best synonym for a particular purpose - for no reason except its sound. In this way the ideal word might emerge - as it has in the past. (Ultimately, for the sake of simplicity there should be no synonyms within the IAL.)
(2) A suitable word already existing in a living language should always be chosen in preference to a neologism. The latter might be more logical, etymologically speaking, but only the test of time proves euphony.
(3) The extant original form of a word should be used rather than transliterated versions in other languages.
(4) Justice demands that the IAL's vocabulary be selected from all languages. In fact this is not a limitation, since things and ideas tend to originate in different countries - and often the best of them in small nations, within minority tongues. The other side of this coin is the requirement to maximise phonetic range and depth, so as to minimise the number of homographs in an orthographic script.
(5) It might happen that a word chosen for the IAL eventually failed: perhaps because most people disliked its sound, or its historical associations. However, synonyms would continue to exist in the remaining mother-tongues for centuries, so replacing a word in the IAL should not be too difficult.
(6) The globalisation of commodities and ideas is not taking place wordlessly. Thus the same processes that have raised one synonym above others within national tongues have begun to work internationally. In this way the best words for the IAL might appear.
(7) Where synonyms of equivalent pedigree exist, it is probably better to choose the older word, or, where that cannot be established with certainty, the shorter. In many cases the shorter word, or - more exactly - the word requiring less effort to articulate, will be the older word (Zipf's Law).
(8) Whereas the IAL is unlikely to borrow Chinese characters for its script, it might adopt the Chinese system of word-formation - as imitated by progressive constructed languages.
(9) Where it is impossible to choose between alternative words, and a compromise word has failed, it may be necessary to return to first principles. Did Cratylus identify one of these in Plato's eponymous dialogue? He pointed out that rho is a sign of motion, found in words such as "tremor, tremble, strike, crush, bruise, tremble and whirl" because it is linked to the physical activity of pronunciation. According to Socrates, the tongue was "most agitated and least at rest in the pronunciation of this letter" and therefore it was originally used to express motion. Aspirated phonemes requiring expenditure of breath, likewise find themselves in windy, tempestuous words such as "shivering, seething, shock and shaking". Lamda, with its liquid smoothness produced by the slipping of the tongue, is found in words like "slip, level, floor, flood, sleek" (when combined with another syllable it denotes easy but repetitive motion as in "handle, swivel, anvil, paddle"); gamma, in which the tongue is detained, combines with lamda to express the notion of stickiness, as in "glue, glutinous, glucose".