Many phoneticians consider them, or at least the glottal fricative, to be transitional states of the glottis without a point of articulation as other consonants have, while some[who?]
For example, in Literary Arabic, most words are formed from a root C-C-C consisting of three consonants, which are inserted into templates such as /CaːCiC/ or /maCCuːC/.
They instead represent transitional states of the glottis (phonation) without a specific place of articulation, and may behave as approximants.
Often all vocalic onsets are preceded by a glottal stop, for example in German (in careful pronunciation; often omitted in practice).
The Hawaiian language writes the glottal stop as the ‘okina ‘, which resembles a single open quotation mark.