Most of the grammar outlined here is morphology: how words change to mark different meanings. This includes noun declensions, verb conjugation, and more. A distinction is made between inflectional morphology, where words are marked without changing which part of speech they are (i.e. -s, -ed, -ing), and derivational morphology, where words change between parts of speech (i.e. -er, -ism, -ness). The remainder involves things like particles, small words that are mostly meaningless on their own but take on meaning when placed by other words.
Repair strategies are a part of morphology. They dictate how when the correct form of a word would make it unallowable under the phonotactics, a language fixes the word to be allowable. In Wetejo, there are two types of repair strategies; one for loan words, and one for morphology.
For loan words, the strategy generally goes as follows; first, take each sound and morph it to the closest Wetejo sound; English /iŋgliʃ/ becomes inklis. Then, add vowels after all consonants where they are needed. The vowel that is chosen is generally a duplicate of whatever is the vowel immediately before or after. inklis would become inkilisi.
The morphological repair strategy is actually quite simple. Nearly all problems with morphology arise when an affix adds an onset or coda to a syllable which already has one, i.e. pik- + téloke or enján + -n, or when a root that typically has an affix attached is left without one. In the case of a prefix, the vowel of the syllable after the offending consonant is placed immediately after it, creating a new syllable (piketéloke). The reverse is done with a suffix, reduplicating the final vowel in the root (enjánan). Certain affixes have a fixed repair vowel, so the reduplication doesn't happen and instead the specific vowel is inserted: ilón + -(e)nlo = ilonenlo. A spot for a reduplicated vowel is represented by (V).
Another repair strategy is for when too many (usually two or more) vowels are adjacent to each other. An -n- or -l- is inserted to differentiate the vowels; -l- after a-, -n- anywhere else. This is known as the diphthong repair strategy. It is not always clear whether or not it should be used, and in unclear cases it is usually specified on the affix or root with a (C). (l) or (n) can also be placed on an affix, implying that that consonant and not the other should be used for repair. If we wanted to combine fe- (the perfective suffix) with énnolan "we are flying" (to make "we fly"), we would insert -n- between to differentiate the two es: fenénnolan "we fly".
Finally, occasionally mmorphology can result in /ij/ or /ji/. This is seen in the 3sg conjugation of kanje "to name", which is kanjili. In such cases, the j is simply omitted.
Nouns decline for case and number. Number, of course, consists of the plural suffix -(V)n; any other numerical information is encoded with words. There are 6 cases: Absolutive, Ergative (Subjects of transitive verbs), Dative (for indirect object), Genitive (for possession), Locative ('at' or 'to'), Ablative ('from'), and Inessive ('in', 'into'). All of these are marked by simple inflectional suffixes: Ergative is -o, Dative -(n)an, Genitive -so, Locative -(l)i, Ablative -(C)udon, and Inessive -(C)on. Numerical declensions are applied before case declensions. Often, the Inessive case can be the same as plural; context will differentiate between them. The cases of the noun alonin "church" are as follows: alonin (Abs), alonino (Erg), aloninan (Dat), aloninso (Gen), alonini (Loc), aloninudon (Abl), and aloninon (Ins).
Verbs conjugate for agreement, tense, and aspect, and we will discuss these in that order. Verbs are divided into two groups based on the end of their root form; consonant and vowel.
First, agreement. Verbs agree with the person and number of the subject. First person (at least in the present tense) is marked with -(C)a, second person -(C)i, and third -ili. Number is marked after person with -n. For verb roots ending with -a, the 1sg present form is the unmodified root word (while 1pl follows the normal pattern). In roots ending with -i, 3rd person merges with 2nd.
Then, we have tense. Below is a chart of the conjugations of the verbs tonke 'to walk' and niankale 'to drink' for tense, person, and number in imperfective aspect, realis mood. 2nd and 3rd person have merged in past plural and future singular, as well as past singular for consonant-final roots.
Infinitive is marked with a -(V)e suffix.
More details on why I chose these conjugations (warning: large block of text):
I'll take you through this in the same order I decided things.
First was C-final present, from which I would derive most of the other conjugations. -a, -i, and -ili, the basic conjugations, I decided on simply because I liked the phonaesthetics. -n was already the plural suffix for nouns, so it made sense to use it here as well. That gave me six conjugations already.
Then was C-final past. I settled on deriving most of these from a basic -(l)o suffix . I decided that tonkililo was difficult to pronounce, even though it was allowed by the phonotactics, and by pronouncing the word over and over again I determined that the second i was problematic. This led to tonkilo, so that it merged with the 2sg form. A similar thing happened with 3pl past, which turned from tonkilino to tonkino.
C-final future came next, and after trying a few other forms I settled on reduplicating the previous vowel. If this resulted in an unallowable word, as it did with all the singular forms, I also reduplicated the previous onset. I found the 3sg form difficult to pronounce again, and so once again I merged it with 2sg.
V-final present was next. The first iteration of these forms was simply using the diphthong repair strategy. I realized that the 3rd person suffix -ili worked well enough without it, so took away the (C) there. I considered merging 3sg and 2sg again, given that -Vili and -Vli are very similar, but decided against it. I figured that these forms would be used often enough that native speakers would be able to distinguish them easily (I did end up merging them in past plural). I then realized that, for verbs like niankale 'to drink' (the one with which I'd been experimenting), the basic root form nianka worked well as a ki form. I added this in as an exception, but kept the old niankala form in the plural, niankalan. I wasn't certain about this, seeing as I liked the phonaesthetics of niankala, but eventually I decided the shorter, more copmact nianka would become dominant.
V-final past was very regular. The only irregularity I introduced was merging 3pl with 2pl, as niankalino and niankailino were definitely not common enough to be distinguishable.
V-final future is probably the strangest set of conjugations at first glance. The ki form is perfectly regular, but not beyond that. I decided it didn't make sense for a consonant that exists because of a repair strategy to be reduplicated, so instead of niankalili I made the 2sg form niankalii. Of course, this called for its own diphthong repair, and so I ended up with efa niankalini. For awe (3sg), I decided that it made sense to merge it with 2sg, even if only for uniformity's sake. In any case, niankailili would be very difficult to pronounce. The kin and efan forms were also regular, but not 3pl awen niankalinni. This, I decided, would just be an irregularity.
Above I have outlined the conjugation rules for subject agreement and tense. The next important thing to think about is aspect. This essentially defines how an action or state extends over time; 'I was helping people' vs. 'I helped people'. These two sentences have the same tense, but are distinct from each other in meaning. The examples also nicely fit with two aspects distinguished in Wetejo; imperfective and perfective respectively. There are two others, Inceptive and Cessative, marked with ek- and jek- respectively, which correspond to beginning and ending an action. The imperfective is shown above and is the unmarked form. Perfective is marked by the prefix fe-. Present perfective is generally interpreted as a habitual aspect, but the system generally works as written otherwise.
Modality is mostly periphrastic, not grammatical, but I will outline it here regardless. The realis mood is unmarked, and the particle o marks the irrealis mood. There is a set of mood words similar to those in English that mark the different modalities.
The simplest form of valency is the passive voice, or changing a verb from transitive to intransitive. This is simply accomplished by having ku replace the absent subject; it was held is ku awe atenilo. The verb is conjugated for the absolutive noun as is typical of intransitive verbs.