The Weekend's TV: Fry's Planet Word, Sun, BBC2<br/>Fighting on the Frontline, Sun, Channel 4

You may not have wanted a tour of Stephen Fry's oesophagus to round off the weekend, but that's what the opening sequence of Fry's Planet Word offered you anyway, the lens rising through his pipes along with the breath that expelled his first word, "Hello". Seventy muscles and half a million brain cells went into that, according to Fry – not a boast, as it happens, just a register of the complexity of human speech.

I don't mind admitting that I was a bit nervous at this point in the proceedings. That title was a bit twee, for one thing, and there's always a danger, when people start enthusing about words, that things can get precious very fast. It's usually less than 30 seconds before someone starts wittering on about how lovely the word "serendipity" is, so when Fry said of language that "it's what I treasure above all else... it is what makes me, me", it sounded ominously as if we might be in for a "celebration" and all that entails.

Happily, it was better than that – a beginner's guide to the curiosities of linguistics that began at the Max Planck Institute for Evolutionary Anthropology in Leipzig, where Fry talked to a developmental psychologist about the difference between instinctive communication (which is what animals do) and advanced speech. Monkeys, Michael Tomasello explained, can learn to use pictograms or rudimentary sign language, but their utterances tend to be entirely couched in the imperative, and almost exclusively concerned with their own desires. He seemed to feel that this was evidence in itself of their exclusion from the realm of true language – though I know some human teenagers of whom precisely the same could be said.

After that, Fry bearded another scientist, an evolutionary geneticist who'd narrowed down the source of the enormous evolutionary advantage language gives us to a gene known as Fox P2. Alter just two amino acids on that gene and the chimps – it was suggested – might have gone beyond simply ordering more peanuts to writing poems about them. This man had spliced the human version of Fox P2 into some laboratory mice. I hoped, for one mad moment, that Fry might be able to conduct an interview with them: "Well, the accommodation leaves a lot to be desired, frankly, but the work is intellectually stimulating and we don't have to worry about food bills." Sadly it turned out that they just squeaked a little bit differently now.

Linguistics has always had a way of throwing up dodgy interventions, beginning with the monarch who isolated a child from birth in the cruelly misplaced belief that it would end up talking Hebrew, as the ur-language of the human race. We met his modern counterpart here in the form of d'Armond Speers, a computational linguist, who taught his baby son Klingon as his first language, using the Klingon Imperial Anthem as a lullaby. Quite why Mrs Speers didn't put her foot down about this wasn't revealed, but very sensibly the child declined to continue the experiment the moment it had any choice in the matter. And then, continuing an excursion into the nature of artificially constructed languages, Fry "talked", if that's the word, to two deaf signers, to discover how they developed new proper nouns. Barack Obama, it turned out, was an emphasised O that modulated into a waving flag, while Adolf Hitler involved a brilliant gestural shorthand that required no translation: lift your right hand, palm down, to your nose and lay the thumb along your top lip. Tip the fingers upwards. Congratulations, you've just signed Hitler. If, like me, you were nervous about fluting verbosity, don't be – it's learner-slope linguistics, yes, but nicely done for all that.

The nasty things you can do with language didn't get much of a look in in Fry's Planet Word, but they were very much apparent in Fighting on the Frontline, Channel 4's contribution to the growing number of programmes devoted to the war in Afghanistan. "What do you think goes through the Taliban's heads when they see an Apache coming?" asked an offscreen female voice. "Hopefully a 30-mil bullet," a pilot replied deadpan. Comic exploitation of ambiguity, you see, which monkeys can't do. Nor would they think to use "Vampire" as the code word to alert a field hospital that you've got a casualty with really serious blood loss. Or, I think, come up with the concept of Kill TV – a post-operation briefing at which the ground crew get to enjoy cockpit footage of a £50,000 missile taking out a man who can do just as much damage with a weapon costing $30. Disturbing and gripping television.

t.sutcliffe@independent.co.uk