 Stops that are fortis (or 'strong') are differentiated from those that are lenis (or 'weak') on the basis of length of closure, as opposed to the voice onset time (VOT), the period after the release of the stop before the commencement of vocal fold activity (or voice) which normally differentiates fortis and lenis stops in English and most other languages.Lenis stops in Wagiman sound like English voiced stops and are therefore written using the Roman alphabet letters "b", "d" and "g".Fortis stops, however, sound more like voiceless stops in English, but are slightly longer than lenis stops.