Consonant sequences include NC (homorganic nasal–plosive), where C may be /b d t d̠ ɟ ɡ k/. Elsewhere, /b d/ are relatively rare and only occur before high vowels. /d̠/, written ⟨ḓ⟩ in the literature, is a laminal post-alveoral coronal stop that is indeterminate as to voicing. The phonemic status of [ʔ] is unclear; if [VʔV] is interpreted as vowel sequences /VV/, then this contrasts with long vowels (where the two V's are the same) and vowel sequences separated by linking glides (where the two V's are different).
Steinhauer, H. (1991). "Problems of Gorontalese phonology." In H. A. Poeze and P. Schoorl (Ed.), Excursies in Celebes: een bundel bijdragen bij het afscheid van J. Noorduyn als directeur-secretaris van het Konninklijk Instituut voor Taal-, Land- en Volkendkunde, 325-338. KITLV Uitgeverij.
^Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, eds. (2017). "Gorontalo". Glottolog 3.0. Jena, Germany: Max Planck Institute for the Science of Human History.