New York City English, or Metropolitan New York English, is a regional dialect of American English spoken by many people in New York City and much of its surrounding metropolitan area. Described by sociolinguist William Labov as the most recognizable dialect in North America, the dialect is known through its association in the media with many public figures and fictional characters. Its features are most densely concentrated in New York City proper and its immediate suburbs (whose residents often commute to New York City), but they also extend somewhat to the wider metropolitan area and the New York City diaspora in other regions. The dialect is widely known for a number of both conservative and innovative pronunciation features, such as a lack of the cot–caught, Mary–marry–merry, and hurry–furry mergers; r-dropping (except before a vowel); a high, gliding /ɔː/ vowel (in words like talk and caught); and a split of the "short a" vowel /æ/ into two separate sounds.
The origins of New York City English are diverse, and the sources of many features are probably not recoverable. New York City English, largely with the same major pronunciation system popularly recognized today, was first reproduced in literature and also scientifically documented in the 1890s. It was then, and still mostly is, associated with ethnically diverse European-American native-English speakers. New York City English likely evolved from an older English variety that encompassed much of the larger Middle Atlantic region, including the Delaware Valley (whose unique dialect today centers around Philadelphia and Baltimore), since the New York City dialect and the Delaware Valley dialectal offshoots all still share certain key features originating nowhere else the United States, such as a high /ɔː/ vowel with a glide (sometimes called the aww vowel) as well as a phonemic split of the short a vowel, /æ/ (making gas and gap, for example, have different vowels sounds), though the New York City variant of this split remains distinct from the Delaware Valley variants. Linguist William Labov has pointed out that a similarly-structured but distinct-sounding short-a split, often called the trap–bath split, is found today in the southern half of England, including London, and that both this short-a split and the distinctive one now heard in the New York City and Delaware Valley dialects may therefore have a common ancestor originating in the 1800s.