This paper examines clitics in colloquial Vietnamese. In Vietnamese, a clitic is a syllable that appears as a reduced form in casual speech and exhibits a phonological dependency on the material to its left. Only the tone of the former function word remains, while all its segments may be replaced. If the host ends in an obstruent, the clitic surfaces as a homorganic syllabic nasal. If the host ends in a vowel or a glide, the clitic surfaces as a lengthened part of that vowel or glide, unless it has a nasal rhyme, in which case it surfaces with its own nasal.