All the same, it looked alarming at first. Jean Aitcheson's opening salvo against such linguistic pillars of correctness as the single negative and the un-split infinitive caused R4 listeners to rise up in agitated defence, but, by the end, she showed herself to be a cheerful, inventive custodian of our gloriously versatile language. Her sheer cleverness, coupled with a beguiling wit, proved fascinating and instructive. The Language Web that she described is a system of word storage and retrieval so endlessly intricate and sophisticated as to make the Internet look like a tea-strainer. Her material was complex and her delivery, at first, monotonous, but she wisely broke up the steady flow of information with snippets of birdsong, baby-talk and Blackadder, to give her listeners grasping-space; by the final lecture she sounded almost chatty.
This last one warned us about the language of persuasion. Often, it is all too obvious - cue an enraged ranter at Speaker's Corner inveigh- ing against the godless and accursed BBC - but sometimes we are unaware of the perils of veiled metaphors. They can be downright dangerous: English-speakers are so used to being frozen by terror, for example, that they just might forget to run away.
Using a fine simile herself, she compared a good communicator to a cook with a lemon, squeezing the essence from a message and allowing it to flavour the entire speech. But metaphors are powerful weapons and must be used carefully, she warned. They should be sufficiently ear-catching to make people take notice but sufficiently ordinary to be acceptable.
There was a lesson in this for Marius Brill, whose plays about a blind detective are currently provoking late-night unease. Uncomfortably named S-laughter in the Dark (R4), this series is more tightly filled with verbal tricks than - oh, than a vacuum-pack with coffee. The plot of the latest, Donne to Death, was overheated, but the language was feverish. "I was determined to get to the bottom of this," says the detective, while we wait nervously for him to add: "faster than an Italian's hand". Well, all right, but it won't do for a bereaved moth- er to explain, with carefully articulated brightness, "I'm never very good first thing in mourning."
It just doesn't work, however irresistible the playwright found the pun. Nor does this: "Families - they make you feel like bad food: they're really not satisfied until they've brought you up." Back to the library. Mr Brill, for a little more study of linguistic anatomy.
Language is the stock-in-trade of John Sessions, so it was perverse of him to take on the role of Stan Laurel, whose humour was so visual. Sessions produced a tour de force a fortnight ago for R3's Mightier than the Sword, but the interview he gave to Debbie Thrower (R2) on Monday suggested that he might be better at impersonating types than real people, particularly when he has no sympathy with them. Thrower is an excellent, intelligent interviewer, polite but steely when provoked. Sessions arrived at the studio hungry and couldn't wait for his sandwiches. He talked, I think, about preferring verbal wit to Laurel and Hardy's slapstick. To hear him express such sentiments while munching breadily was to understand why your mother was so insistent about not speaking with your mouth full. Thrower's courtesy was audibly assailed, but unbeaten, by this lack of it in her guest.
It boded ill for Tom McGrath's play, Laurel and Hardy (R4), and this time the forebodings were well-founded. Sessions produced a voice like Laurel's, sometimes - especially when he said "I'm at ruck-buttum, Ullie". At other times, however, it sounded more like a Michael Howard-style Welsh, but in reverse, ending on a morose downbeat - less sing-song than Sing Sing. By this stage he had taken the voice from Lancashire to Glasgow to Hollywood, adapting it all the way, so we shouldn't grumble. But he never stopped being Sessions. Robbie Coltrane did better as Ollie, but the play was oddly mawkish, a double autobiography nostalgically narrated by self-justifying ghosts, accompanied by a solo piano and some crashing props. Another fine mess.
The week's most moving programme came later that night with the first of a new series of Soundtrack (R4). When Esther was admitted to hospital, her mother, afraid that she might never hear her daughter's voice again, determined to record her, and the tape became an audio-diary. "I'm going to make sure that everybody learns from this experience," she resolved. "We chose to believe the experts and they were wrong."
Esther had been ill for four months, but nobody believed her. Her mother tried like blazes to get help, but was uneasily persuaded to accept a paediatrician's opinion that the bright little seven-year old was just playing up. It was a shocking tale. The neuro- surgeon who eventually removed her brain tumour chose his words carefully: "All physical symptoms have psychological aspects to them," he said, "but a primarily psychological explanation should be at the bottom of the list." Too right, Mr Clark. But if even a self-confessed stroppy middle- class mother is fobbed off, what will happen to other Esthers?
There were agonising minutes of hearing the child's loud, rhythmic moaning and the parents' gathering despair before we learnt that she did indeed pull through, her voice less giggly, but her spirit sparkling. It was a vast relief to hear her naughty brother finish- ing the tape for her. "Hi, pig- face ..." he said, before being forcibly silenced.