Dash it all Jeeves, you've failed the test Could P G Wodehouse have written better with a grammar checker? David Bowen doe sn't think so

The late Sir Pelham Grenville Wodehouse was a master of the English language. Luckily he did not have Grammatik 5, or he could have been a very confused master.

I typed a passage from Stiff Upper Lip, Jeeves into my computer and set Grammatik to work on it. It is a grammar-checking program that operates like a spell check, highlighting what it believes are problems in a window on the screen. It soon had cause tocomplain about the passage where Bertie Wooster has just bumped into the ferocious Roderick Spode: "He was eyeing me piercingly, little knowing what an ass he was going to feel before yonder sun had set."

Apart from objecting to ass ("Avoid this offensive term"), Grammatik declared that "the verb `going' does not normally take an object". It thought "ass" was the object of "going", having failed to spot the significance of "to feel".

Grammatik - which came with my WordPerfect for Windows word-processing package - is full of such nonsense. Checking the first two pages of the novel Nice Work by David Lodge, Honorary Professor of Modern English Literature at Birmingham University, it queried "worries streak towards him" because "streak is usually preceded by an article". In other words, it thought streak was only a noun. It wanted to put a comma after "supposing" in "supposing it is only six o'clock".

Grammatik, which is produced by Reference Software International of San Francisco but is available in a British version, is a sophisticated piece of software. It does its best to cope with the rules of English, and tries hard to be flexible. It has 10 predefined writing styles, which allow varying degrees of informality ranging from the strict "business letter" to the supposedly liberal "fiction". You can also tailor your own style if, for example, you cannot tolerate sentences of more than 10 words. As a computer program, it is admirable: easy to use, clear and powerful.

However, it is beaten hands down by the English language. As any foreigner will tell you, English is riddled with exceptions and inconsistencies, and can be generated correctly only by that most subtle computer, the human brain. Grammatik might do a goodjob in logical languages such as French or German - but English? No.

Perhaps, I thought, I was being unfair in putting Grammatik up against masters of the language, so I ran 1,000 words past it from an article I wrote recently. Some of its suggestions were reasonable. It highlighted sentences it thought were too long. It scolded me for starting three sentences in a row with the same word. And it pointed out that two of the previous 10 sentences were passives. All points worth contemplating, even if Grammatik's allergy to passives is stronger than mine.

But it also grabbed the wrong end of the stick with depressing regularity. It would not accept my use of "mighty" as an adjective; it tried to make me play cricket by changing "first half of the century" into "first half century"; and it did not want me to talk about a "16-foot model bridge"; it should have 16 feet, apparently.

It is difficult to see a real use for grammar-checking programs. People who have a good grasp of grammar will scoff at their foolishness and ignore them; those who are not so strong are likely to find they have introduced more errors than they have banished.

Grammatik does, however, make users think of the structure of language. The British version, largely based on classics such as Gower's Complete Plain Words and Fowler's Modern English Usage, is an excellent tutorial that could warrant installation of theprogram on its own. It is comfortingly conservative, abhorring the use of "hopefully" in the place of "I hope", for example. And it's easy to get lost in "help", wandering happily from fused sentences to formalisms.

The educational role is enhanced by a number of extras. At school I remember having to underline nouns in red, verbs in green and adjectives in yellow. Grammatik will do this for you, displaying the part of speech of every word underlined.

It also has a diverting "fog meter" program to tell you how readable your prose is. Using three different equations, it will produce the Flesch-Kincaid Grade Level, the Flesch Reading Ease score and Gunning's Fog Index. All three are based on the same factors: the number of words per sentence combined with the number of syllables per word - so it seems unnecessarily gimmicky to include them all.

But they are harmless enough, made even more amusing by the ability Grammatik gives you to compare your writing with that of the greats (and the not-so greats). Your work can be examined for easy reading; the number of sentences per paragraph; average words per sentence; and average letters per word with Churchill's speeches (all of them), an unspecified Graham Greene novel, and a life-insurance policy.

The Flesch ease of reading scoreboard looks like this: P G Wodehouse 80, Graham Greene 80, David Lodge 70, Winston Churchill 69, myself 59, life insurance company 45.

Before editing, this article had an average paragraph length of 3.7 sentences, an average sentence length of 16.6 words and an average word length of 1.54 syllables. It had a Flesch ease-of-reading score of 60. Could do better.