[8] Edwards (2015) demonstrates that pronouns, numerals and many affixes in Enggano can be directly derived from Proto-Malayo-Polynesian.

[11] While a large portion of its lexicon obviously cannot be derived from Proto-Malayo-Polynesian, it remains unclear whether this represents a non-Austronesian substratum from an unknown source language, or the result of internally-driven lexical replacement.

[12] He notes that Enggano possesses many aberrant phonological features (such as a small phonological inventory) and a low lexical retention rate, which is more typical of Austronesian languages spoken in eastern Indonesia and Melanesia than rather than those of western Indonesia.

[13] Some non-Austronesian languages in Southeast Asia, such as Nancowry, Semelai, and Abui also have low lexical retention rates.

However, the discussion of phonology is limited to a simple inventory and a short paragraph of basic features.

Yoder and Nothofer report seven oral and seven nasal vowels:[21] Diphthongs are /ai, aɨ, au, ei, ɘi, oi/.

(Nothofer counts these as consonants /j, w/ restricted to initial position, which avoids the problem of not uncommon [ji] being analyzed as /ii/, when sequences of the same vowel are otherwise quite rare.)

An intrusive vowel [ə̆] appears between glottal stop and another consonant (though not semivowels), as in /kaʔhɨɘ/ [kaʔ.ə̆.hɨ.ɘ] 'female leader'; this does not affect the pattern of stress.

Yoder notes that the voiced stops [b~m, d~n] are in complementary distribution, depending on whether the word has nasal vowels (similar to Guarani), but lists them separately.

Kähler's dictionary adds /ɲ/, as well as /f tʃ dʒ/ as marginal phonemes, and claims that /t r/ are only found in southern villages.

However, Yoder states that at the time of his research in 2010 there were no differences among the six villages on Enggano Island, and that initial /t r/ and final /t d/ are rare in native words.

Medial /d/ and /r/ are in free variation in a few words, with older people preferring /d/ and younger speakers /r/.

The main reference on the syntax and morphology of the Enggano language is the grammar produced by Hans Kähler.

This section compares some of the findings in Kähler (1940) with those of Yoder (2011), where the language appears to have undergone some changes.

This is the final vowel of the stem to which the suffix attaches, e.g. euba 'house' > euba'au 'my house', ebohe 'spear' > ebohe'eu 'my spear'.

The pronouns listed in Yoder (2011) are as follows: Most of these appear to be Austronesian: Compare Malay 1sg aku ~ ku, 1.EX kami, 1.IN kita, 2pl kalian, 3sg/pl dia, and suffixes 1sg -ku, 2sg -mu, 3sg -nya, with *k, *t (d), *l, *m, *n having shifted to ’, k, r, b, d in Enggano, and with final consonants and (where possible) vowels being lost.

According to Kähler, verbs are typically marked with the prefix ki- or bu- (allomorphs b-, mu-, m-, -ub-, -um-) or occur in bare form.

Verbs in bare form take a different set of agreement markers and occur following the negator keaba'a (§ 15).

[22] In addition to ki-, bu- and bare forms, Enggano verbs can take further derivational morphology:[32] Attested prefixes in Yoder (2011) are ba-, ba’-, ia-, iah-, ka-, ka’-, kah-, ki-, kir-, ko-, pa-, pah-, ’a-.

Compare the remaining -hai’, -ru, -kər, -up, -rib with Lampung əsay, rua, təlu, əpat, lima; *s, *t, *l, *m have shifted to h, k, r, b in Enggano, and final consonants and (simple) vowels have been lost.

The two forms for eight mean 'hugging', from the verb pã’ĩõp 'to hug', and nine appears to be 'eight, one coming'; it may be shortened to kaba kahai’ (no -i) in enumeration.