Latin teaches or reinforces understanding of the parts of speech through its case, declension and conjugation structure. Very few of my present pupils have more than the haziest understanding of the functional difference between a noun and a verb, even in a simple example such as: 'Shall we take a walk?' and 'I walk to school'. That means there is no commonly understood vocabulary for discussing potential problems such as practice/practise or who/whom. And try explaining to a mainstream English class today that 'lain' is the past participle of the verb 'to lie'. The result of this ignorance is that the accuracy of spoken and written English spirals downwards.
We learnt how to construct grammatically sound sentences. Each must have a finite verb, usually a subject and often an object, along with one or more dependent clauses and so on. Some Latin syntactic structures are directly transferable into English - 'I saw the man to be very tall' (accusative and infinitive) - in spite of some English teachers' condemnatory arguments. Even where the constructions do not work in English, analysis of them teaches accuracy and attention to detail, as well as knowledge about the way language works.
What about spelling? English is a frustratingly difficult language to spell. Very often, however, the spellings of thousands of Latin-derived English words can be clarified by learning the origin of the word. For example, words that originate in first-conjugation Latin verbs usually have an 'a' - as in culpable, duplicate and ambulance. Second-conjugation verbs always have 'e' in the stem, as in sedentary, apparent and deterrent. You do not need to be an advanced Latin scholar to have a basic grasp of all this.
My O-level Latin course improved my spelling, and I am sure it could do the same for many of today's pupils if they were given a year or two of Latin. It is hard indeed to learn the capricious ways of English spelling without any kind of hook on which to hang the learning.
The joy of unravelling the rich vocabulary of English and its history is lost if pupils have no knowledge of its sources. Latin is a prime source. Consider 'scribble', 'scribe', 'script', 'manuscript', 'inscribe'/'inscription', 'prescribe'/'prescription', and so on, which come from the Latin 'to write' - scribo, scribere, scripsi, scriptum. A child who has been taken through this group and helped to see how the words interrelate, perhaps setting them against those from the Greek graphos and the old English writan, is really beginning to learn about his or her language.
Latin is also a wonderful tool for vocabulary extension. I well recall first encountering 'hostile', 'amatory' and 'valediction' among hundreds of other words in Latin classes as the teacher strove to relate Latin to our own language. Today I occasionally teach the delicious patterning of Latinate word groups in English lessons. We might look at 'regicide', 'patricide', 'suicide' or 'canine', 'feline', 'lupine', but it is a thin substitute for the pupils having enhancing vocabulary drummed into them several times a week.
Because Latin was the language of our most powerful institutions - the church, the law and the universities - fragments of it are all around us. We put PS at the foot of our letters whether they are written at 11 am or 11 pm in this year of 1993 AD. Students use nb, eg, ie. Doctors perform post mortems and write 'per nocte' on sleeping-pill prescriptions. I try to remain compos mentis while not getting caught in flagrante delicto and if I am well, nil desperandum. My salary is assessed per annum and as a teacher I often have to stand in loco parentis. Latin a 'dead' language? Absurd.
Today's pupils should be taught some Latin: I can think of no surer way of effecting an improvement in knowledge and handling of English in the young. Sadly, Latin is gradually disappearing from state schools. The national curriculum is displacing it. Only about 15,000 candidates now take the subject at GCSE; in the Sixties it was 47,000. We are already paying the price: those who bewail the low standards of English in school leavers should be campaigning for the restoration of Latin.
The writer teaches English at a high school in the home counties