English actor, comedian, writer, and director Stephen Fry in an interview with with Sameena Ali-Khan on ITV News:
The average sitcom in America is based on real jokes—real, terrific one-liners and fast-talking wit. In contrast, great British sitcoms are centered around characters, usually portraying a failure. The great comic heroes of Britain share a common theme—they all try to be grand in a world that lets them down. Whether it’s Captain Mainwaring in Dad’s Army, Harold Steptoe in the long-running sitcom Steptoe and Son, Tony Hancock, or Leonard Rossiter in Rising Damp, the same holds true for Basil Fawlty with his ties and blazers, and Alan Partridge and David Brent of “The Office.” they are all failures, hopeless characters who believe they are great but struggle to comprehend the modern world and fail to interact with it properly. In contrast, an American would never have a failure as a comic hero. The American hero is faster, sharper, and cleverer.
British and American sitcoms differ significantly in their tone, humor, and portrayal of characters. Notable distinctions are evident: British humor is marked by subtlety, wit, and dry humor, frequently employing wordplay, irony, and clever dialogue. British sitcoms tend to adopt a more understated and nuanced comedic approach. In my opinion, this subtlety often contrasts sharply with the overt nature of American humor, which highlights punchlines, physical comedy, and situational humor, characterized by a broader and more explicit comedic style.
In terms of characters, British sitcoms often depict individuals who are more flawed, socially awkward, and prone to failure. There’s a tendency to explore the ordinary aspects of life, finding humor in everyday situations. The focus lies on characters’ reactions to their circumstances, deriving humor from their consistent quirks and flaws. Conversely, American sitcoms frequently incorporate character development and growth into their storytelling.