Phonological History of English High Front Vowels - Weak-vowel Merger

The weak-vowel merger is a phonemic merger of /ə/ (schwa) with unstressed /ɪ/ (sometimes transcribed as /ɨ/ or /ᵻ/) in certain dialects of English. As a result of this merger the words abbot and rabbit rhyme; in accents without the merger they are distinct. The merger is nearly complete in the Southern Hemisphere accents and General American, and complete in Hiberno-English.

Even in accents that generally maintain the distinction, it may still likely merge in other circumstances:

• /ər/ and /ɨr/ have merged in virtually all accents when they occur at the end of a word or before consonants. These two sequences are otherwise less likely to merge before vowels, but still more likely to merge than /ə/ and /ɨ/ alone. In Received Pronunciation, this became /ər/ before vowels, and /ə/ elsewhere. In General American, this became /ɚ/ in all positions.
• /əl/ and /ɨl/ have merged in most accents when they occur at the end of a word or before consonants (especially if the /l/ is dark ), becoming /əl/ or /l̩/. In accents where /ɨl/ survives, it is usually realized as /ɪl/ and may not be a articulated as a weak vowel at all; in modern Received Pronunciation and General American, this tends to sound archaic or stilted.
• /ən/ and /ɨn/ have merged into /n̩/ after /t/ or /d/ in both Received Pronunciation and General American, creating the sequences /tn̩ dn̩/. /tn̩/ in particular often simplifies to . The weak vowel may reappear when a word is enunciated syllable by syllable.

The following end differently for speakers without the merger:

• ribbon, cabin
• carrot, merit