Thilceidac, as a Tharcaic-Merinic language, has an accusative alignment, made up of two particles: -o for the nominative (derived from the ending Th-M *-u) and -oθ for the accusative (derived from the ending Th-M *-un), but, from contact with Claebajarc, it has developed split ergativity for sentences with a neuter nominative subject and when the verb is transitive of Claebajarc origin, developing the particle -θρa (derived from the particle uθ and the -r ergative ending from that language).

The order of the constituents of the sentence in Thilceidac, as in all Tharcaic-Merinic languages, is free, except for sentences with ergativity, where the order is ERG-NOM-V, because it is a structure received from Claebajarc.

The only verbs with a conjugational paradigm are kura ("to be"), lek ("to stay) and takθ ("to have"). As for the rest of the verbs, the transitive ones are formed with the periphrasis participle+kura and the transitive ones with the periphrasis participle+takθ. They can also be made as participle clauses (the participle is always located at the end of the clause). As for the sentences with ergativity, these are made with the participle+kura or with the participle alone.

"The dog ate the bird"

kaltu-uθ urs̩sθ takki keura-o

kaltu-uθ keura-o urs̩sθ

"The bird was eaten by the dog"

kaltu-o urs̩sθ takoθ u keura

kaltu-o u keura urs̩sθ

"The wind knocked down the wall"

keuntu-θρa reinteukm̩-uθ fiθ kurasi

keuntu-θρa reinteukm̩-uθ fiθ

"The soldier killed the man"

oss̩km̩-θρa krila-uθ kraθ kurasi

oss̩km̩-θρa krila-uθ kraθ