The Antarctican language has many regional varieties, mainly distinguished by vocabulary (borrowed from other local languages spoken in the area). It is much less common for regional varieties of Antarctican to differ in their syntax and phonology. Indeed, the local languages spoken across Antarctica almost always share certain syntactic and phonological features, forming a very strong Sprachbund[*]. Even though most of these languages are descended from completely unrelated languages from across the world, over time, they have converged to acquire certain areal features. Some examples of these are:
- A pitch register system Register[*].
- Consonant voicing only being phonemic under certain specific conditions. In particular, a total lack of phonemic voicing of non-coronal fricatives.
- Some kind of fortis / lenis contrast in obstruents, which often interacts with the pitch register system in some way. This contrast may be glottalisation (ejective or implosive), gemination or aspiration.
- Two sets of nasal consonants (this can be plain vs. prestopped, or involve a voicing contrast).
- A very restricted range of syllable shapes.
- Ergative-absolutive case marking on nouns (if any is present at all).
- A complete lack of number agreement on verbs, and no comprehensive marking of plurality on nouns (only ever specific categories of nouns).
- Tense and aspect are not consistently marked on verbs, if they are marked at all.
- A lack of infinitive verb forms. Antarctican languages use a variety of ways to compensate for this.
- Transitivity marked on verbs.
- Syntactic ergativity.
- Topic-comment structure to sentences.
- Inclusive and exclusive 'we', with no distinction made between exclusive 'we' and 'I'.
- Head initial syntax.