SIAL is designed as an International Auxiliary Language. The morphology is a priori, while the general lexicon is a posteriori, and the syntax is a mixture.
Orthography and Phonology
Letters and Sounds
SIAL uses the latin alphabet (of which H, Q, and X occur only in proper names) with no diacritics.
- A, E, O, I, U are always used for vowels [a, e, o, i, u],
- P, T, K, B, D, G, C, J, F, S, V, Z, M, N are always used for consonants [p, t, k, b, d, g, tS or S, dZ or Z, f, s, v, z, m, n or N],
- R, L are also used for consonants (they have the most phonetic variation and note that they have complimentary distribution outside of proper names),
- Y, W are sometimes used as consonants [j, w] and sometimes as unstressable vowels [i, u].
Syllable structure is (C(L))V(C). The onset clusters which occur include TR, DR, PL, BL, KL, GL, KW, GW.
Geminates of nasals and voiceless obstruents may occur; these are written using double consonants: PP [p:], CC [t:S], etc. except that [S:] is written SC. The geminate RR also occurs.
The consonant clusters SP(L), ST(R), SC, SK(L), SKW, and geminate RR may occur word-initially in the citation form and in speech or writing when the immediately preceding word ends in a vowel. Otherwise, a vowel is added (E before RR and I before the others) to preserve the syllable structure given above.
Stress is on the penult with a few exceptions (mainly stressed monosyllables and maybe some proper names).
SIAL has only a few inflection and derivational affixes.
The main lexical classes are verb, noun, and particle. Note that these are distinct from the similarly named syntactical classes.
The final vowel of an inflectable verb or noun determines its syntactical class. These are:
|-A||preposition or divalent verb with explicit object|
|-E||adverb, secondary predicate, or verb without explicit object|
|-O||noun, adjective, or other noun modifier|
|-I||vocative (only on head word of phrase)|
|-U or none||some proper nouns|
There's also a non-final suffix -AZ. It's technically a role inversion suffix, but for inflectional purposes is used as a passive marker.
Where both mood and aspect are marked, the mood prefix appears first. Where aspect is unmarked, a dynamic lexical verb is aoristic and a static lexical verb is stative.
SIAL is basically S-V-O-P and D-Q-A-N.
The general vocabulary should be as international as possible. This means that there are a lot of words derived from Latin, some from Greek (most numeric), and some from various other sources.