Imagine for a moment that you are an astronaut. You've crash- landed on an alien planet and, within seconds, are surrounded by little green creatures no higher than your knee who burble away at you in an incomprehensible series of clicks and chirps. You'd probably feel confused, isolated and at a loss to tell whether the situation you were in was threatening and hostile - or whether what was being communicated was the Martian equivalent of "Come inside and have a cup of hot tea after your long journey."

Now imagine that you've just stepped off a boat and onto the shores of an island in South-East Asia. A gang of taxi drivers jostle for your custom and leaflets for hotels that range from fleapit to beachside luxury are thrust in your face. It's hard not to feel confused.

The two situations are not dissimilar, the only difference being that when you encounter humans, whatever the gap in verbal communication, body language goes a long way towards creating a mutual understanding of mood - wherever you are in the world, you'll have a good idea as to whether the person talking to you is about to invite you in for a meal or level a shotgun at you.

Language is a hallmark of humanity, such a constant, such a given, that we feel disoriented when we are put into situations where we are unable to communicate.

English speakers are fortunate in that - thanks in part to the pervasiveness of pop music and Hollywood films - the great majority of people around the world speak at least a few words of their language. And that's not even taking into account those countries where English is either the first or the second language, of which there is a long list.

Having said that, there are many countries where English will do you little or no good unless you happen to be conversing with a member of an educated elite. Few people in many Latin American countries, for instance, have more than a few words, if any, of English, and trying to get around without a basic Spanish vocabulary - enough to order a meal, book a train ticket or ask for a hotel room - can make the going nearly impossible. I once spent six weeks in Peru with a friend who was under the impression that Italian was close enough to Spanish to enable him to get by. By the end of the first week in the country, he had been reduced to near-despair by his inability to communicate the simplest of needs.

Even those countries where English is widely spoken can prove tricky to negotiate without a few words of the native tongue. Travelling round Israel many years ago, I ended up in Ashkelon when I was meant to be heading for Eilat, simply because I couldn't ask my fellow passengers which direction the bus was following.

Many people criticise the British for their apparent inability - or unwillingness - to make the effort to learn even the merest smattering of a new tongue. Europeans, in particular, tend to be vocal in their criticism of the English traveller who believes that by speaking a little bit slower and a little bit louder he will make his audience understand whatever it is he happens to be talking about. Many Europeans, particularly northern Europeans, take the trouble to learn to speak excellent English - so why should it be so hard, they feel, for the English to take the trouble to pick up a few words of the language of whatever country they happen to be visiting? And they could have a point.

Even those early faltering steps in a new tongue - learning how to say please and thank you, for example - go a long way towards creating an atmosphere of trust: people are usually delighted that you have made the effort. Go a bit further and learn how to ask the price of things in a shop or marketplace, book a hotel room or enquire into the state of someone's health, and a whole new world will start to open. And forget that very British concept of being embarrassed about using the wrong words, the imperfection of your grammar or your awkward accent. Most people you encounter will be more than happy to make allowances for your mistakes.

So if you're planning a trip, what's the best way of getting to grips with the language? The most elementary way, of course, is to buy a phrasebook. These are now carefully researched and marketed, and there is very little chance that you will come across one that contains outdated, clunky and irrelevant sentences. The best way to find one to suit you is to go into a bookshop and browse through as many versions in your chosen language as possible. Try and get an idea of the range of situations covered to make sure your kind of travel experience has been catered for. If you don't even want to go that far, most guidebooks have a section dealing with useful words and sentences.

There are some severe limitations to this approach, however. To begin with, although these books are usually sorted into questions and their related (potential) answers, the chances of someone responding by the book, so to speak, to your carefully phrased question are pretty slim. Just think of the number of ways you might answer a tourist who asked you for directions to a particular museum or restaurant, for instance, and you'll get some idea of why things can get very confusing very fast. And local accents and idiom can muddy the waters even further.

Perhaps less limited are the 'teach yourself' type of book, which gives you step-by-step lessons in a language, from the basics ("My name is...", "How much is...") to the expression of more complex ideas. These will usually give you a fuller appreciation of a language than a phrasebook would, especially as you can gain some insight into its grammatical framework, helping you to construct sentences which you have never actually been taught. However, you may still run into problems with the spoken language once you arrive at your destination. Cassette tapes can be helpful in giving you a taste of how a language is actually spoken, but will not help you explore it in any greater depth than a book would.

The best approach - if you have the time - is to take some lessons before you leave home. If you are based in London, both Floodlight and On Course publish details of courses in languages that range from Arabic to Urdu, at various levels ranging from beginner to colloquial. Buy one of these guides well in advance of the start of term, as some courses book up quickly, and check the listings to find your nearest centre - chances are you'll find one near work or home. Classes are usually held in groups of anywhere from five people to 20, and all should give you at least an elementary facility in your chosen language. If you have a helpful teacher, he or she should be able to advise you on useful phrases for situations that you expect to encounter on your travels and will be able to recommend additional reading matter that may prove useful once you've mastered the basics.

If you need to learn an Oriental or African language, the School of Oriental and African Studies (SOAS) at the University of London teaches everything from basic Yoruba to Chinese poetry and runs both full- and part-time courses. SOAS is based near Russell Square (tel 020 7898 4888, fax 020 7898 4889, email languages@soas.ac.uk, website www.soas.ac.uk/languagecentre).

Other centres focus on one particular language, but run courses that vary in their intensity, duration and the degree of expertise required from you. The Institut Français in South Kensington (tel 020 7581 2701, fax 020 7581 2910, email michel.richard@ambafrance.org.uk, website www.institut.ambafrance.org.uk) is renowned for the quality of its tuition, and covers everything from French at work to an appreciation of french literature. The Istituto Italiano di Cultura (tel 020 7823 1887, fax 020 7823 2887, email italian.languageservices@gateway.net, website www.italcultur.org.uk) and the Instituto Cervantes (tel 020 7245 0621, email cenlon@cervantes.es, website www.cervantes.es), both of which are based in Belgravia, cover Italian and Spanish (respectively) in equal depth. Japanese is taught at the Institute of International Education in London, which is situated in the heart of Regent's Park (tel 020 7487 7678, fax 020 7487 7679, email humanet@dircon.co.uk); and Russian courses to suit all levels of experience are conducted by The Russian Language Experience (tel 020 7608 3794, fax 020 7608 3792, email Russian_Language@compuserve.com). Most of these organisations run one-on-one sessions, which might suit your needs better than group lessons.

Another way of finding a good tutor is to go to the language department of your nearest university and place an ad on the college noticeboard. The chances are that you'll end up in touch with a number of very fluent students who would be only too happy to pick up some extra money in exchange for a few private lessons. Alternatively, someone at the language department itself may be able to recommend a professional tutor.

Finally, if you have the time, the most thorough way to immerse yourself in a new language is to sign up for a residential course based in the country itself. Lessons are usually conducted during the morning, leaving you free to explore your surroundings and practice your lessons in a real-life situation in the afternoon. Accommodation ranges from very basic beds in student halls to thoroughly luxurious palazzi; alternatively you might like to stay with a local family, a crash-course experience that forces you to be brave and plunge right in and try out your new-found language skills.

Whichever method you choose for learning your new language, the amount of effort you put in will pay rich dividends in allowing you to enjoy travel experiences that would once have left you feeling like you'd just arrived on a spaceship from an alien planet.