Lojan

Phonotactics
Possible syllables are: Impossible clusters are: When an affricate or a plosive precedes a fricative of the same place, they merge into one affricate.
 * (C)(C)(C)(C)V(C)(C)(C)(C) for primary words
 * VC(C)(C)(C)V(C)(C)(C)(C) for secondary words
 * No limit for compound words
 * /t/, /th/, /d/, /dɦ/, /s/, /z/, /t͡s/ or /n/undefined+ /ɾ/. (In these occasions, /ɾ/ will be substituted by /r/

Assimilation Agressive:
 * /gk/ > /kk/, /tht/ > /tt/, /tdh/ > /ddh/, etc.
 * /tʈ/ > /ʈ ʈ/, /t  ʈ h / > / ʈ ʈ h /, /t ɖ ɦ / > / ɖ ɖ ɦ /, / t  ʂ / > / ʈʂ / > / ʈ͡ʂ /  etc.

Vowel Grade
In Lojan, vowels have 3 grades:

Primary, secondary and compound words
Primary words only have one syllable. Secondary words have two syllables but the first is always without onset. Compound words can be formed from primary, secondary, o even other compound words.

Forms
Almost every word has three main forms: Absolute Form(AF), Dependent Form(DF) and Predicate Form(PF).


 * AF works as a noun or a pronoun. Also, AF can form the non-head parts of a compound word.

​Primary and secondary words can transform by vowel grade shift: Compound words don't have PF,  and their forms(AF and DF) are related with the head place. The AF has the initial head place, while the DF has the final head place.
 * DF, just as its name, cannot appear independently. It can accept particles or enclitics. When a noun is suffixed by a particle/enclitic, it must change from AF to DF. Also, DF can act as the head of a compound word.
 * PF is simply a verb, from which the adjective form can be formed.
 * "full, long": "Full" for the first vowel of the secondary word, "long" for the second.

Sentences, like compound words, also have AF, and DF. And the AF has the initial head place, while the DF has the final head place.[ If a sentence has a topic(omitted or no), the topic is its head, or the head will be the verb.]

Cases
Noun cases are expressed by particles (like in japanese).
 * khu, "flower". khūikj, "towards the flower". (remember that particles must be attached to DF).
 * dang, "sky". dāngtaṅ, "in the sky".

​Plurarity
Lojan nouns don't decline according to number, but there are other ways to express the plurarity:

Collective words
Compounding a noun with a collective word:

Numerals
Numerals can be directly put before a noun:
 * guq dhrim. "a person".
 * sim sir. "six lions".

Duplication
For compound words, only duplicates the head: If a word needs change its form, all the duplicated parts should change at the same time.
 * gak, "star". gaggak, "(some) stars"
 * dhrim, "person". dhrimdhrim, "some persons, people"
 * khūkhir, "flower of snow". khūkhūkhir, "flowers of snow".


 * gāggākikj, "towards the stars".

Pronouns

 * Some forms of some pronouns are irregular. (erābī, sos)
 * Plurarity is expressed in the same way of nouns.

Adjectival form
Most words have adjectival form, whose meaning is related to its AF's meaning.( But there are no rules for this relation, so its necessary to remember the meaning of the adjectival form).
 * khu, "flower" > khosr, "beautiful"
 * lug, "a far place" > logsr, "far"
 * gas, "I" > gåssr, "egoist"
 * vis, "wind" > vessr, "free"