There are four basic ways wehreby words enter a language. There are the original words, so old we can trace them no further. In English, this is a handful of Celtic words. Next, there are imposed words: those forced upon a people by their conquerors. After the Celts, these were the Romans, the Anglo-Saxons (including the Jutes), the Danes, and the Norman-French. Finally, there are invented words and borrowed words.
Word Ways: Vol. 14
, Article 15.
Available at: http://digitalcommons.butler.edu/wordways/vol14/iss3/15