English is the international language of business, science and information technology. So people of all ages from all walks of life all around the world take classes or individual tuition to learn the basics and keep their skills up to date.

If you are planning a long stay in a specific country, teaching English as a foreign language (TEFL) is a good way of getting to know the locals. English is in demand in the largest cities and the remotest locations. Teachers can find salaried positions or volunteer placements, as long as they have the relevant qualifications and a working visa.

With the high demand for English lessons, a TEFL qualification is not always necessary, but to avoid disappointment when you get to your destination, it is best to have at least a basic certificate under your belt.

Many different TEFL courses are available. Some programmes last over one month, but you can take an intensive weekend TEFL course, or an online option.

As with any course, ask the organisers searching questions before you sign up. For example: What are the main components of the course? How many people are in the classes? Does it include teaching practice with real language students? Is the qualification internationally recognised?

The Cactus website, which has advice about different courses and qualifications, is a good starting point. "It's a good idea to be very clear about the job prospects associated with each course type before you take the plunge," it says.

Cactus arranges admissions for various Cambridge CELTA (Certificate in English Language Teaching to Adults) and Trinity CertTESOL (Certificate in Teaching English to Speakers of Other Languages) courses.

It notes: "There are small differences between these, but the overriding similarity is that they are externally assessed and moderated by well-known exam boards. They are 'level 4' qualifications as recognised by the Qualifications & Curriculum Authority and every single course which runs is inspected by someone appointed by the exam board."

"These courses run as 4/5-week full-time courses, or as part-time courses, and are very intensive, but have to be the best guarantee to find work when you are starting out in TEFL."

The Career Break Site has a section on TEFL. "If you want to go straight into a job," it advises "use a course provider that has its own schools abroad."

The British Council has information about higher professional diplomas and degrees in TEFL.

To meet growing demand, many online TEFL courses are offered by companies on the Internet.

As language teaching itself is interactive, you will have to weigh up the advantage of being able to complete an online course quickly with the disadvantage that online courses lack an interactive component with real students.