The short and simple answer is, No. If you are tired and cannot sleep, then watch television. If you enjoy American football or baseball, watch television. If you are too ill to work or walk, watch television. But if you want to improve your English, or your own language for that matter, then read a book or magazine, go to the pub, talk to a friend, study something - anything - in the language, take up collecting American pop songs or English postage stamps, find a hobby which will connect you to the country, write long letters in the language to a penpal in Nepal... Anything, probably, is better for you than watching television.

Many of the students I have met in London have been advised by their teachers to watch television. Upon what evidence the advice is based I do not know. Do you suppose those teachers could learn Arabic or Chinese by watching television in Cairo or Beijing? I have my doubts. I even came across the case of a language school selling intensive courses of which two hours a day were used for television watching. This made good commercial sense in that it is cheaper to slot a movie into a video than employ a competent teacher.

Maybe students already know that watching TV is useless for language learning, and they are asking me if it is good for them in order to see if my advice in other areas can be trusted. Certainly this approach is used by training managers who want to check a teacher’s competence.

Research among small children has now made clear that television is worse than useless. It actually does you harm. Some harassed mothers have the habit of parking their babies, like cars, in front of the screen. In Britain, a research unit checked a sample of 300 such babies, all from the same social background. The researchers discovered that at the age of three those infants who watched a great deal of television had a language ability one year behind those of the control group, who did not.

More interesting is the recent American case of the boy born to deaf parents. The child had perfect hearing. Despite watching television for several hours every day, by the time he reached school age, he could not use spoken language at all, although he was perfectly proficient in using sign language with his parents.

[In this connection, it is worth noting that I can sometimes detect students who watch too much television because they do not so much listen to what I say as study my face to see what sort of general response they should have.]

At the moment, the ways of absorbing information are limited. Apart from touch and movement, of which more use could be made when teaching small children, there are only two ways of getting information into the brain: through the eyes and through the ears. The information has to go through the working memory. For most of us, the working memory is extremely limited. As a result, if we are taking in information through the eyes, the working memory closes down input from the ears. A person deep in a book will not hear when spoken to. There are many other simple observations you can make to support this theory. For example, do you hear better when you close your eyes? In the dark, trying to go to sleep, do you become aware of sounds you didn't hear before? Why do burglars choose to go in the back door of houses when they know the family is watching television in the front room? The point the theory makes is that when you concentrate on looking, you don't hear so well. If you don't hear, how can you learn?

These arguments do not mean that television does not have its uses. Firstly, television can be useful for showing how people do things, for demonstrating manners and customs, for showing how to and how not to. Brilliant training films have been made to show salesmen how to sell, interviewers how to interview, plumbers how to plumb. In language teaching, the mechanics of pronunciation can usefully be demonstrated on film. Of course, at this point, we are moving away from television into demonstration videos made for specific purposes.

One of the great advantages of video is that it can, like the audio cassette, be repeated. Repetition, especially repetition which as much as possible avoids boredom, is the key to language learning. A movie can be recorded, and after being watched in the normal way, it can be replayed to listen to, with the video off. The dialogue heard can then be linked in the mind to the memory of the movie or programme as seen some hours or days earlier.

Under these circumstances, television becomes a tool which can be deliberately used by the active and serious independent student as a memorising aid.

Finally, whatever country you are in, people watch television, and they talk about it. If you move in circles in which television is an important topic of conversation, then you may be wise to watch a little, so that you can keep up socially. However, in my opinion, you would be better off glancing down the newspaper column of "What's on TV tonight", and asking next day the simple questions, "Did you see...?" "What was it about?" "Was it any good?" The answers you get will teach you more English than if you had watched the programme in the first place. For conversation, you don't have to watch it. You just have to know what's on.