cotcaught

The cot–caught merger is a phonological phenomenon found in many varieties of North American English in which the vowels in the words cot and caught are merged, so speakers who have the merger pronounce these words with the same vowel. In dialects that retain the distinction, cot and caught are pronounced with two different vowel qualities.

Historically, cot and caught come from two back vowels: cot with a low back vowel and caught with a mid back vowel. In merged dialects, both words share a single vowel realization, though the precise quality of that vowel can vary across dialects and individual speakers. The merger is often described as a back vowel merger, but its exact phonetic realization is not uniform.

Geographic and social distribution varies widely. The merger is common in much of the Western United States, large parts of Canada, and many Midland and Inland North varieties. It is less consistent in the Northeast and in many Southern dialects, where a cot–caught distinction remains for many speakers. Within regions, there is further variation by age, gender, and community background, with some studies suggesting the merger is spreading among younger speakers in certain areas due to dialect contact and leveling, while other communities show stability in the distinction.

In linguistic research, the cot–caught merger is a classic example of how regional speech patterns shift and spread. It is often analyzed alongside other vowel shifts and mergers to understand patterns of dialect contact, social identity, and language change.