The English language has been shaped by a number of other languages over the centuries, and many English speakers know that Latin and German were two of the most important. What many people don't realize is how much the French language has influenced English.
Without going into too much detail, I want to give a little bit of background about the other languages which shaped English. It was born out of the dialects of three German tribes (Angles, Jutes, and Saxons) who settled in Britain in about 450 A.D. This group of dialects forms what linguists refer to as Anglo-Saxon, and at some point this language developed into what we know as Old English. This Germanic base was influenced in varying degrees by Celtic, Latin, and Scandinavian (Old Norse) - the languages spoken by invading armies.

Bill Bryson calls the Norman conquest of 1066 the "final cataclysm [which] awaited the English language." (1) When William the Conqueror became king of England, French took over as the language of the court, administration, and culture - and stayed there for 300 years. Meanwhile, English was "demoted" to everyday, unprestigious uses. These two languages existed side by side in England with no noticeable difficulties; in fact, since English was essentially ignored by grammarians during this time, it took advantage of its lowly status to become a grammatically simpler language and, after only 70 or 80 years existing side-by-side with French, Old English segued into Middle English.

Would our friends agree with the above description? How the language English was born has explained in the above.

The dialect of three German tribes was the root of English. I haven't heard this theory before.
In my opinion, current English has its root in the language spoken by the children whose father was a settler from Scandinavia and whose mother was an Anglo-Saxon. If you take 1000 English words most frequently used in everyday speech, they are either of Anglo-Saxon origin or of Old Norse origin. The influence of the French language is rather minor. It is true that English vocabulary contains many words of French origin but most of them are words that are used only in speech or writing of higher registers.

It is also true that the conquest by the French Norman greatly impacted on the English language. But the impact was rather an indirect one. The French conquerors paid no attention to the English language for 300 years after the conquest, and as the result, English was rapidly vulgarized. During that time all of the official documents were written in French and there was no school where English was taught. English at that time remained a language spoken only by uneducated people of the lower class who were descendants of the Scandinavians and Anglo-Saxon mixed children. It was that three centuries when the English language drastically changed in the grammar. Old Norse (the language spoken by their father) and Old English (the language spoken by their mother) were similar in vocabulary, but the case declensions and the verb inflections were a bit different. So the children of the mixed race dropped the case declensions and simplified the verb inflexions in order to communicate with both their parents. Thus the basic grammar frame was renewed into the one close to the current English's.

I am interested in the fact that similar simplifications took place in vulgarizing classic Latin to Romance Languages (French, Spanish, Portuguese, Italian, and etc.). I have an opinion that massive immigration and massive intermarriages tend to accelerate simplification of languages.

Thanks paco for the comments.

I would like to hear what the others say on this.