since about mid 5th century
Expanded answer: The modern English language has its linguistic roots in several ancient Anglo-Saxon dialects known together as "Old English". These dialects began showing up in England during various waves of migration and invasion during the 5th century. Old English is closer to German and Old German than it is to what we today know as English, and is unintelligible (in either written or spoken form) to English users that have not had special education in the ancient language. Old English and English are not really the same language, though the latter developed from the former. "Beowulf" was written in Old English.
Old English began transforming into "Middle English" with the first of the Norman invasions in the 11th century, which added a strong French influence to the language. "The Canterbury Tales" are written in Middle English. While many words are recognizable to modern English users in print (with many spelling and grammar differences), the spoken language is pronounced in ways that would not be used in the modern language and would be unintelligible to modern English users. It should be considered a separate language.
"Modern English" dates from the mid-15th century, alongside what is called the "Great Vowel Shift". As the phrase implies, the tone or phonetic value of some vowels were changed. Also, the meanings of some common words changed. During this time period, the English government spread the common usage of a London dialect, and the use of printing presses helped standardize spelling. By the time of Shakespeare's plays, the English language had become what we today would call "English", even though there were still many differences in individual spellings and of course there were regional dialects and accents as there are today. Fluent users of written English should be able to read modern printings of Shakespeare's works without trouble. Modern printing is specified because printers of the day used some typesets and characters that made printing easier, or were common abbreviations, which are not used today and can obscure meaning for those who are unaccustomed to seeing them.
So, the answer is: The language that English speakers use today in the 21st century is only about 500 or 600 years old, though it has its roots in ancestor languages that are up to 1500 years old. A very large portion of modern English vocabulary is even younger, dating back to only the last few hundred years, as scientific and technological advances have led to concepts (and words to describe them) which were unthinkable in previous centuries.
Longer than the English language has been around, which is 1500 years anyway.
Modern English has been around since approximately 1400, long before the English language arrived in North America.
The English borrowed the Latin alphabet from the Romans around the 8th or 9th Century CE. Before that, the English used Norse runes to write Old English
how long has deforestation been around
As long as guns have been around.
how long has the london eye been around for
As long as So Random has been around.
New England was first used as the name for the new English settlement in Massachusetts in 1620.
They have always been around
boner
how long have boxing been around?
234 years fool