How many times has great Britain been invaded and what effect did this have on the English language?

Answer 1

This a complex question for a short answer. Essentially, Britain has been invaded around four times, once by Celtic-speakers from the mainland (largely replacing Neolithic peoples who are remembered only as "Picts", and whose language replaced the prior languages. The Romans came later, having little linguistic effect but leaving behind their law and social customs.

Later came the Angles and Saxons who gave us the term Anglo-Saxons as well as Jutes who did not. From present-day Denmark, Holland and Germany. Their languages largely supplanted Celtic in England (much less so in Scotland and Wales) and became Old English. There were also many settlements founded by Vikings from Norway and Denmark especially in the North of England, and coastal Scotland and Ireland, and this could also be termed an "invasion".

The last invasion was by Norman French (the descendants of Vikings- "Northmen", who had settled in France, specifically Normandy) in 1066 who spoke a dialect of French called Norman French. Their linguistic impact was profound, if not immediate. Many words of Norman French origin came into English (note, Norman French was different to that spoken in say Paris, as examples the words "chattel" and "cattle" are French and Norman respectively). Later, under the influence of the Normans (who fostered the Church), many Latin words entered English.

There were later influences on English, not brought about by military invasion, too complex to cover here.