Here's what I know about the grammar of Graavgaaln:

Word order is SOV.

Pronouns and nouns show case. Object, Benefactive and Instrumental are
attested and marked with suffixes.  Locative is handled with a postposition.

Number is marked on nouns.

Possessor-possessed. Possession is shown with the word <nezh> which comes
between the two  persons/objects being related.

Verbs show number, person and tense and causation.

Coordination of NPs uses the word <lÓ> between the terms. Coordination of
clauses uses the word <nezh> both before and after the second clause.

I need to go back over my few texts and see what other information I can