Verbs are negated using the prefix pyu–, which goes before any conjugation prefix. This prefix triggers vowel harmony. If the word (including conjugation prefixes) starts with an unrounded vowel, the vowel or diphthong that was at the beginning of the word is deleted. If the word (including conjugation prefixes) starts with a rounded vowel, the prefix changes to pyup–. The prefix is added to modals instead of the main verb for modals listed below, except for thee, where it goes on the main verb.
Some words aren't used with this prefix, in some or all senses, and instead a separate word is used to indicate the negative. These are noted in the lexicon. Examples include altha/upmul (have/lack) and postural verbs expressing location/myumoyho. Eshtea "want" is not usually negated; rather, its argument can be negated.
Each verb has a prefix indicating tense, aspect, and mood. There are two types of verbs, strong verbs and weak verbs; strong verbs typically start with vowels or w and take prefixes for most common tenses/aspects/moods; weak verbs typically start with consonants and use modal verbs (shown in green below) to indicate forms other than the past indicitave and past dubitative forms.
Strong verbs are conjugated as follows:
Past
Both
Present
Future
Conditional
Perfective
Imperfective
Stative
Stative
Continuous
Stative
Indicative
Direct
∅
la'–
el–
j–
eis–
∅
shl–
lh–
Reportative
l–
lal–
li
lais–
l–
alh–
Inferential
et–
tetl–
e'j–
tets–
et–
etlh–
Dubitative
Any
se'–
sel–
sel–
selj–
ses–
se'–
sheshl–
selh–
Inferential
set–
setl–
eta selj–
sets–
set–
setlh–
Protasis
lhaþl–
lheþ–
lheþ lh–
Optative
hashl–
hesh–
hesh lh–
Prot+Opt
lheshesh–
lheshesh lh–
Imperative
(disfix)
Common
eth–
thee lh–
Weak verbs are conjugated as follows:
Past
Present
Future
Conditional
Perfective
Imperfective
Stative
Continuous
Stative
Indicative
Direct
∅
la'–
la'–
eis
∅
shleh
lheh
Reportative
al–
laa–
lais
al–
alheh
Inferential
e'–
te'–
teteis
e'–
etlheh
Dubitative
Any
se'–
sela'–
sela'
seleis
se'–
sheshleh
selheh
Inferential
eta se'–
eta sela'–
eta seleis
eta se'–
eta sheshleh
eta selheh
Protasis
lheþ la'–
lheþ
lheþ lh–
Optative
hesh la'–
hesh
hesh lh–
Prot+Opt
lheshesh
lheshesh lh–
Imperative
∅
Common
thee
thee lh–
Suffixes
–ha (or –a after a fricative) forms stative verbs from active verbs, indicating the state that the active verb causes (e.g., if applied to the word for break, this would give the word for to be broken). Not all verbs can take this suffix, and depending on the verb, this suffix may or may not change its arguments (i.e., it acts as a passive voice for some verbs). I'm considering verbs using this suffix to be separate words.
Reduplication of the last syllable forms the habitual aspect. If the first sound in the last syllable is a stop and the final vowel is long, the stop becomes voiced and non-aspirated in the reduplicated syllable. This works for (almost) any active verb.
–nai forms verbs relating to ability. It can be used on (almost) any verb. Verbs with this suffix are treated as stative verbs.
–aiþ indicates that the statement seems to be correct.
–lyh switches the subject and direct object of stative verbs.
–s turns stative verbs into adjectives. The s replaces any coda consonants on the verb and causes the final vowel, if it's long, to become short.
Tense and aspect
Tense indicates the tense relative to the time of speaking. Stories tend to use the past tense.
The main aspects are distinguished in the past only. Present tense generally indicates actions that are currently going on or states that a person or object is currently in. Which aspects a verb can be conjugated in depends on whether the verb is active or stative; stative verbs are indicated in the lexicon with the abbreviation st. Verbs marked in the lexicon with nt. are always conjugated as if they were present stative verbs, regardless of their actual tense; such verbs may be missing some moods as well.
Meaning of the aspects:
Perfective (prefixes, past only) indicates a complete action, without talking about what was going on during the action. It only be used on active verbs.
Imperfective (prefixes, past only) indicates an action that was ongoing at the time in question, and provides background for other actions happening at the same time, for actions that interrupt the imperfective action, and for details about the action in the imperfective.
Stative (prefixes) indicates a state has already existed at the time in question. It can only be used on stative verbs. Stative past has two different forms depending on permanence: if a state is known only to exist in the past, or is something that tends to be nonpermanent, the el–/la'– form is used; if a state is known also to exist uninterrupted in the present, or is something that tends to be permanent, the j– form is used (identical to the gnomic in weak verbs).
Continuous (prefixes, present only) indicates that an action is in progress. For statives, it can be used to focus on the tense and it can be used to indicate that the state is more temporary than would otherwise be assumed.
Habitual (reduplicative suffix) indicates that an action occurs more than once. This is mainly used on active verbs. If the action is habitual in the present, it's conjugated as if it were happening in the past (perfective aspect), unless indicating present tense is necessary for clarity or focus. For indicating that an action was habitual in the past, use eslaha.
Gnomic (auxiliary verb i) indicates that something is always the case.
Mood
Any mood may be used in the main clause of a sentence; additionally, verbs that can take clauses as arguments may require certain moods. The following moods are indicated by the verb's prefix:
Indicative is used for ordinary declarative sentences. Indicative sentences mark for evidentiality, i.e., how the speaker knows the information in the sentence.
Dubitative is used for when the speaker is uncertain about the statement, and is also used in all neutral questions. It is otherwise similar to the indicative. It can optionally be marked for inferential evidentiality.
The protasis mood is used in a few different places:
In conditions (the conditions themselves, not what follows from the condition). See sentences.
Making a guess, or proposing one possible explanation, without any strong statement that the speaker thinks this is a good idea. (Think of brainstorming...)
Optative indicates the speaker's wish or hope.
Condition + optative is used for proposing a possible solution ("maybe we should...").
Imperative is used to give commands. For strong verbs, the vowel at the beginning is removed.
Common indicates something the speaker assumes the listener already knows. When a sentence uses this mood, the verb comes to the beginning of the sentence, and it is acceptable to omit arguments that would otherwise be required.
Conditional indicates that the sentence is true if some other condition is true. Verbs with this mood do not mark tense or aspect, but it can be combined with other moods.
Indicative past, present, and gnomic sentences obligatorily mark where the speaker's information came from. Other moods may optionally mark this as well, using particles before the verb. These particles can also be used if one wants to focus on the evidentiality (in which case, the verb is conjugated as if it were using the direct evidential).
Direct is used for things the speaker has directly experienced, because they've seen them, heard them, participated in them, etc. It is also used in fictional stories. Its particle is ea.
Reportative is used for reporting things learned from someone else. Its particle is ela.
Inferential is used for things the speaker deduced logically from something else. Its particle is eta. It also has a conjugated form that can be optionally used in the dubitative mood.
Objects
Objects go in the order and have the cases specified in the lexicon (usually the dative comes before the direct object, which comes before any locative objects). Ordinary transitive verbs get one object, which is unmarked for case.
Verbs meaning "to be"
There is no single verb that has all the meanings of English "to be".
Linking nouns (this is my house, that is a cat): eif
Linking adjectives (this cat is black): the adjective itself is a verb
Linking locations (the cat is on the table): various words, see locations
Expressing existence (there is a cat): various words, see locations