Primarily in Austroasiatic languages (also known as Mon–Khmer), in a typical word a minor syllable is a reduced (minor) syllable followed by a full tonic or stressed syllable. The minor syllable may be of the form /Cə/ or /CəN/, with a reduced vowel, as in colloquial Khmer, or of the form /CC/ with no vowel at all, as in Mlabri /kn̩diːŋ/ 'navel' (minor syllable /kn̩/) and /br̩poːŋ/ 'underneath' (minor syllable /br̩/), and Khasi kyndon /kn̩dɔːn/ 'rule' (minor syllable /kn̩/), syrwet /sr̩wɛt̚/ 'sign' (minor syllable /sr̩/), kylla /kl̩la/ 'transform' (minor syllable /kl̩/), symboh /sm̩bɔːʔ/ 'seed' (minor syllable /sm̩/) and tyngkai /tŋ̩kaːɪ/ 'conserve' (minor syllable /tŋ̩/). This iambic pattern is sometimes called sesquisyllabic (lit. 'one and a half syllables'), a term coined by the American linguist James Matisoff in 1973 (Matisoff 1973:86).

Sometimes minor syllables are introduced by language contact. Many Chamic languages as well as Burmese^[1] have developed minor syllables from contact with Mon-Khmer family. In Burmese, minor syllables have the form /Cə/, with no consonant clusters allowed in the syllable onset, no syllable coda, and no tone.

Some reconstructions of Proto-Tai and Old Chinese also include sesquisyllabic roots with minor syllables, as transitional forms between fully disyllabic words and the monosyllabic words found in modern Tai languages and modern Chinese.