English is a widely-spoken Terran language. The influence of the United Kingdom (and its once empire, through a vast colonization program) and later the United States of America saw English gain dominance on Earth over the centuries. English was an official language in such nation-states as Canada, Ireland, Australia and New Zealand.
What we recognize as English emerged in 1066 by the Norman invasion of Anglo-Saxon-controlled England during the Battle of Hastings, with the Norman-controlled influence over the Anglo-Saxon English strongly influencing Old English, a form of German. The mix of Anglo-Saxon- and Latin-based languages created the initial English language. The Great Vowel Shift, between the 13th and 17th centuries, created the shift from Middle English to the Modern English in use today.
The Latin and Germanic influences can be seen in the diversity of words English has for use, usually bearing more than one word for an idea. For example, English bears both the German-influenced "clear" and Latin-influenced "transparent" as words for meaning "to be able to see through". This makes it a preferred language of choice as it remains one of the most expressive languages, adapting words from various languages and sources both internationally and galactically for use in the language. Unfortunately, the mixture of two different grammar types makes English an extremely difficult language to learn as its structure is not always consistent.