Perhaps we could work something like this into Oh Doctor Beeching? Or perhaps not

Perhaps we could work something like this into Oh, Doctor Beeching? Or perhaps not.And, once again, character is everything. Elaine's lines could only be spoken by Elaine, Kramer's by Kramer. And the equal existence of four pals allows four lots of funny lines and witticisms - all going with the grain.This is a process taken to its most successful limit in Friends (C4, Friday), the cult du jour. "It's easier for women not to do it than for a man," Jerry tells Elaine.

"It's part of our lifestyle." Meanwhile George's Jewish mother, who catches him at it, tells him that it's "too bad you can't do that for a living". Jerry Seinfeld, his mates George (small, bald, unsuccessful), Kramer (an extraordinary cross between Eraserhead and Herman Munster) and sassy Elaine (pretty, bright, sparkling) had a contest to see which of them could go for longest without having recourse to self-love. Sanders is being plagued by a woman who claims she is pregnant with his child and her proof is that she can describe a large round birthmark, connected to two smaller ones, at the base of his penis "Jesus, Larry!" says his manager. "She knows all about little Mickey!" Worse, it transpires that actually this woman has gained this knowledge from giving Sanders a "handjob in a parking lot". So, competition time: name one British sitcom character you can imagine being tossed off by a walk-on in a multi-storey.Yes, male or female. For in Seinfeld (BBC2, Monday, Wednesday, Friday), one episode was entirely devoted to the question of men or women masturbating (without the word being used once).

By and large our attitude towards sex, as depicted on TV and in films, is still in the Carry On tradition of double entendres and falling trousers The Americans are utterly different. The Larry Sanders Show (BBC2, Monday, Wednesday, Friday) stars Garry Shandling as an egotistical chat-show host; a slimy but sympathetic anti-hero. This week, having returned from a chalet in Montana after failing to commune with the woods and the lakes, Sanders was putting his team together again, and going back on air. The process offered real satirical insight into how celebrity works and what happens behind the glittering facade of studio sets - into the creepy slickness of the business itself.But the show was also remarkable for a plot which could never have been conceived for a British show. So, when one of her cameo women friends delivered what should have been a killer- line to a similarly cameo man-friend at a party - "Where is your date, or haven't you inflated her yet?" - it seemed like a gag from a different comedy Great joke, no laughs.

The right lines have to be in the right mouths.There are no such problems in Cybill (C4, Friday), because there are no good jokes in the show. Cybill herself (40, much-divorced, rich, single parent) has only one characteristic - the desire to be young. This has led to a bottle-neck in the show, solved only by the creation of an ultra- trendy teenage daughter, Zoe, whose cool language ("caring as in not, laughing as in about to be") is the one highlight of a dreary 23 minutes.If Ellen and Cybill are both too limited and cosy, there are at least two US sitcoms which are much more uncomfortable and challenging. She has a fat bloke (inadequate, heart of gold) and a thin woman (silly, heart of gold) and not much else.