Although English is not the language with the largest number of native or 'first' language speakers, it has become a lingua franca. A lingua franca can be defined as a language widely adopted for communication between two speakers whose native languages are different from each other's and where one or both speakers are using it as a 'second' language. Many people living in the European Union, for example, frequently operate in English as well as their own languages (where these are different), and the economic and cultural influence of the United States has led to increased English use in many areas of the globe. Like Latin in Europe in the Middle Ages, English seems to be one of the main languages of international communication, and even people who are not speakers of English often know words such as bank, chocolate, computer, hamburger, hospital hot dog, hotel, piano, radio, restaurant, taxi, telephone, television, university. Many of these words have themselves been borrowed by English from other languages of course (e.g. chocolate, hamburger, taxi, etc.), and speakers of Romance languages are likely to have a number of words in common with English. But there are many 'false friends' too, where similar sounding words actually mean something quite different, for example, Italian eventualmente (= in case) contrasts with English eventually (= in the end).
Whatever the spread of English across the globe and whatever its overlap with other languages, there has been an intriguing debate over the years as to how many people speak English as either a 'first' or a 'second' language. Estimates of speaker numbers are somewhat variable. For example, Braj Kachru (1985) suggested between 320-380 million people spoke English as a first language, and anywhere between 250-350 million as a second language. On the other hand David Crystal (1995 and 1997) takes 75 territories where English 'holds a special place' (territories which include not only Britain, the USA, Australia, Canada, etc. but also places such as Hong Kong, India, Malaysia and Nigeria) and calculates around 377 million first language speakers of English and only 98 million speakers of English as a second language.
In 1983, however, Kachru made a prediction which, if correct, means that there are now more second language than first language speakers.
It is not necessarily the case that English will remain dominant among world languages. However, there is no doubt that it is and will remain a vital linguistic tool for many business people, academics, tourists and citizens of the world who wish to communicate easily across nationalities for many years to come.
There are a number of interlocking reasons for the popularity of English as a lingua franca. Many of these are historical, but they also include economic and cultural factors which have influenced and sustained the spread of the language:
A colonial history: when the Pilgrim Fathers landed on the Massachusetts coast in 1620 after their eventful journey from Plymouth, England, they brought with them not just a set of religious beliefs, nor only a pioneering spirit and a desire for colonization, but also their language. Although many years later the Americans broke away from their colonial masters, the language of English remained and it is still the predominant language of the world's greatest economic and political power.
It was the same in Australia, too. When Commander Philip planted the, British flag in Sydney Cove on 26th January 1788, it was not just a bunch of British convicts and their guardians who disembarked (to be rapidly followed by many free settlers of that land), but also a language.
In other parts of the British Empire, English rapidly became a unifying/dominating means of control. For example, it became a lingua franca in India, where a plethora of indigenous languages made the use of any one of them as a whole-country system problematic. The imposition of English as the one language of administration helped maintain the colonizer’s power.
Economics: a major factor in the spread, of English has been the spread of commerce throughout the world, and in particular, the emergence of the United States as a world economic power. Of course other economic blocks are hugely powerful too, but the spread of international commerce has taken English along with it. This is the twentieth-century phenomenon of 'globalization’ described by the journalist John Pilger as '...a term which journalists and politicians, have made fashionable and which is often used in a positive sense to denote a "global village" of "free trade", hi-tech marvels and all kinds of possibilities that transcend class, historical experience and ideology' (Pilger 1998: 61).
Travel: much travel and tourism is carried on, around the world, in English. Of course this is not always the case, as the multilingualism of many tourism workers in different countries demonstrates, but a visit to most airports on the globe will show signs not only in the language of that country, but also in English, just as many-airline announcements are glossed in English, too, whatever the language of the country the airport is situated in.
So far, English is also the preferred language of air traffic control in many countries and is used widely in sea travel communication.
Information exchange: a great deal of academic discourse around the world takes place in English. It is often a lingua franca of conferences, for example, and many journal articles in fields as diverse as astrophysics and zoology.
The first years of the Internet as a major channel for information exchange have also seen a marked predominance of English (though such a situation may not continue). This probably has something to do with the Internet's roots in the USA and the predominance of its use mere in the early days of the World Wide Web.
Popular culture: in the western world, at least, English is a dominating language in popular culture. Pop music in English saturates the planet's airwaves. Thus many people who are not English speakers can sing words from their favourite English songs. Many people who are regular cinemagoers (or TV viewers) frequently hear English in subtitled films coming out of the USA.