In Canadian and American English, a word-medial posttonic schwa is often deleted. This refers to a schwa which follows a stressed syllable. However, schwa deletion only occurs in a specific context.
The following words have a word-medial schwa which can be deleted:
In certain words, however, the schwa is never deleted. This is the case in the following words:
The schwa is never deleted when the schwa is preceded by a sound which is a liquid or alveolar nasal and followed by a sound which is a liquid or alveolar nasal. Another way to state the rule is with distinctive features. It is possible to say that the schwa is never deleted when the preceding sound is +sonorant/+coronal and the following sound is +sonorant/+coronal. The schwa can be deleted when the following sound is +sonorant/+coronal but in such a case the preceding sound must be either -sonorant/+coronal or it must be -sonorant/-coronal. For example, in the word "opera" the /p/ has the distinctive features -sonorant/-coronal and in "listening" the /s/ has the distinctive features -sonorant/+coronal.
Word-medial posttonic schwa syncope is a common rule of Canadian and American English but the rule does not apply in all environments. The rule is blocked when the preceding and following sounds are +sonorant/+coronal. The reason that the rule fails to apply here may be that the sounds have the same places of articulation and thus the deletion of the schwa makes the articulation of the two sounds less salient. Another reason may be ease of articulation. It is possible that with sounds which are homorganic, the retention of the schwa preserves a syllable structure which is not only less marked but also requires less effort to articulate.