Due to the difficulties in communication because of the lack of technology, British English
and American English began to differ in some vocabulary and expressions quite early on. It
was not until the twentieth century, after the introduction of new technology such as radio and
television the two varieties started to use the same word when new terms were introduced.
However, some exceptions can be seen. Svartvik and Leech mention for example that when
the British built their first large multilane highway, they created a new word of their own,
motorway, instead of borrowing the existing American word expressway. Another exception
is that the Americans use cell phone while the British use mobile phone for the same item.
About 4000 words are different in American English and British English; some words are
known in both countries, but many words are not (Svartvik and Leech, 2006:153).