with a mid tone are long while with a low tone are "pulsated". Trager mentions further interaction but does not report the details. Diphthongs In addition to these monophthongs, Taos has five (native) vowel clusters (i.e. diphthongs) that can function as syllable nuclei and are approximately the same duration as the single vowels: Unlike diphthongs in several other languages, each component of the vowel cluster has an equal prominence and duration (i.e. there are no offglides or onglides). The cluster is rare in general; the clusters are uncommon in unstressed syllables. Additionally, the vowel cluster is found in less-assimilated Spanish loanwords. Examples of the clusters are below: {| class="wikitable" style="line-height: 1.1em;" ! Cluster !! IPA !! Gloss |- ! | || 'step-relation' (suffix)'step-daughter' |- ! | || 'race' |- ! | || 'paternal aunt' |- ! | || 'the wind did not blow' |- ! | || 'he is gathering it' |- ! | || 'frying pans' |} The phonetics of the vowel clusters vary in their length and also their quality according to stress, tone, and position syllable structure. The clusters have vowel components of equal length in stressed closed syllables (either primary or medial stress) with mid tone. However, in unstressed syllables and in low-toned syllables (with either primary or medial stress) the first vowel in the cluster is more prominent; in high-toned syllables and in open syllables with primary stress and mid tone, the second vowel is more prominent. The nasal cluster has equally prominent vowels in primary-stressed mid-toned syllables while in closed syllables and unstressed the second vowel is extremely short. The cluster always has the first element more prominent than the second vowel. For the quality differences, the vowel in cluster is raised toward . When short, the vowel in cluster is raised toward . The vowel in cluster is rounded to and is more rounded than the allophone of monophthong adjacent to labials. These allophones are summarized in the table below: {| class="wikitable" style="text-align: center;" ! Cluster !! Allophone !! Environment |- ! rowspan="3" | | | style="text-align: left;" | stressed & mid tone & closed |- | | style="text-align: left;" | low tone or unstressed |- | | style="text-align: left;" | high tone or primary stress & mid tone & open |- ! rowspan="3" | | | style="text-align: left;" | stressed & mid tone |- | | style="text-align: left;" | low tone or