Editing Semivowel (section)

==Contrast with vowels==
Semivowels, by definition, contrast with vowels by being non-syllabic. In addition, they are usually shorter than vowels.{{sfnp|Crystal|2008|pp=431–2}} In languages such as [[Amharic language|Amharic]], [[Yoruba language|Yoruba]], and [[Zuni language|Zuni]], semivowels are produced with a narrower constriction in the vocal tract than their corresponding vowels.{{sfnp|Ladefoged|Maddieson|1996|p=323}} Nevertheless, semivowels may be phonemically equivalent with vowels. For example, the English word ''fly'' can be considered either as an [[open syllable]] ending in a [[diphthong]] {{IPA|[flaɪ̯]}} or as a [[closed syllable]] ending in a consonant {{IPA|[flaj]}}.{{sfnp|Cohen|1971|p=51}}

It is unusual for a language to contrast a semivowel and a diphthong containing an equivalent vowel,{{citation needed|date=January 2010}} but [[Romanian language|Romanian]] contrasts the diphthong {{IPA|/e̯a/}} with {{IPA|/ja/}}, a perceptually similar approximant-vowel sequence. The diphthong is analyzed as a single segment, and the approximant-vowel sequence is analyzed as two separate segments.

In addition to phonological justifications for the distinction (such as the diphthong alternating with {{IPA|/e/}} in singular-plural pairs), there are phonetic differences between the pair:{{sfnp|Chitoran|2002|pp=212–214}}
*{{IPA|/ja/}} has a greater duration than {{IPA|/e̯a/}}
*The transition between the two elements is longer and faster for {{IPA|/ja/}} than {{IPA|/e̯a/}} with the former having a higher F2 onset (greater constriction of the articulators).

Although a phonological parallel exists between {{IPA|/o̯a/}} and {{IPA|/wa/}}, the production and perception of phonetic contrasts between the two is much weaker, likely because of lower lexical load for {{IPA|/wa/}}, which is limited largely to loanwords from [[French language|French]], and speakers' difficulty in maintaining contrasts between two back rounded semivowels in comparison to front ones.{{sfnp|Chitoran|2002|p=221}}