Failure to delete the appropriate schwas can then change the meaning. One or both of the schwas will become giving the pronunciation . Both medial and final schwas are retained. In turn, unstressed schwas are deleted. Without the appropriate deletion of schwas, any speech output would sound unnatural. Final schwas may or may not be preserved in speech. Gujarati has a strong schwa deletion phenomenon, affecting both medial and final schwas. There are no triphthongs, although diphthongs can be followed by schwas in some languages. In other words, all vowels but schwas. Some schwas are obligatorily deleted in pronunciation even if the script suggests otherwise. Schwas occur in pre-tonic syllables, but may be epenthetic. Schwas are often retained in music and poetry to facilitate singing and recitation. In the Coventry area, Schwas are often hyper-corrected to , such as for 'button'.