Etymology
The term "etymology" comes from the Greek words etumologia, logia and logos, with a combined meaning of "study of the true sense of speech." Etymology is the study of where words originate, how they are spelled and the way their meanings change over time.
Old English
The English language is a combination of Germanic languages. The modern form of English began amongst the 5th-century Anglo-Saxon settlers of England. The Germanic tribes invading the eastern coast of Great Britain spoke a number of dialects and related languages. The languages were combined and developed into Old English. Around half of the words used in English spoken today evolved from Old English roots. Many Norse words were added by 8th and 9th century invaders. By 1100, Old English was a dying language.
Middle English
When William the Conqueror, known as the Duke of Normandy, invaded England in 1066, he brought a variety of the French language, called Norman-French, with him and imposed it on the inhabitants of the British Isles. By the 14th century, many French words became common in the English language of the time, known as Middle English. The Great Vowel Shift, with its short vowel pronunciations, started in southern England in the 15th Century and marked the beginning of modern English.
Other Roots
The oldest English words are based on ancient Indo-European languages spoken by tribes originating in what is now northern India. Many common English words derived from Latin, spoken by Italic tribes and the Roman Empire. The ancient Greeks added many common words to English as well as commonly used prefixes and suffixes. The vocabulary of late modern English from 1800 on borrowed many words from Spanish and other Romance languages. Many West African words were adopted into English through the slave trade.