Middle English (ME) was the dominant and traditional spoken language form in many parts of England during the Middle Ages. Though most language historians suggest that prior to about 1000 CE, the primary language in England was Anglo-Saxon, the Norman invasion of England had significant effect on Anglo-Saxon. It gradually morphed the language into Middle English, a form almost recognizable, at least in text, as far more relative to modern spoken and written English.
History can have an intense effect on language. For England, the Norman invasion changed English forever. In the courts and in much of the writing of the time, French was definitely preferable, accounting for the numerous French-based words (over 10,000) that are now the common every day words of today’s English. Most documents dated after 1000 were written in either French or Latin, and Middle English drew from both, while still retaining some of its Anglo-Saxon roots. This in part accounts for the significant “exceptions” in English grammar, spelling, structure and pronunciation that can make English such a challenging language to learn, especially for those acquiring it as a second language.
Despite the use of French in court, Middle English was the language of the people, and few people outside the nobility or the church were readers. Moreover, even with the development of the printing press, books were highly expensive, and few, except for those in the upper classes, could afford them. It’s also important to understand that Middle English was not the only language spoken in England. Scots, Cornish and Welsh all were spoken and differ from modern and even Middle English, and several prominent dialects of ME like the West Midland dialect have significant differences from the “London” form of the language.
As French influence faded, a number of writers from the 12th and 13th century decided to write in the vernacular language, rather than in French and Latin. This tradition spread, and the 14th century produced probably the most important vernacular writer, Geoffrey Chaucer, the author of The Canterbury Tales and Troilus and Criseyde. Important West Midland dialect writers produced two of the classics in English medieval literature, Pearl and Sir Gawain and the Green Knight. The authors of these pieces are unknown and some critics attest the same person wrote them.
You can observe many differences between Middle English and modern form. Many of these are slight spelling differences, and many others have to do with pronunciation of the language. Chief among pronunciation changes from Middle to Early Modern English is the typically French pronunciation of most vowels. What we now refer to as silent “e” was frequently a spoken syllable. Vowel pronunciation of long vowels is as follows:
Long a is aah
Long e is like the a in fade
Long i is like the e in greet
Long o is like the o in fool
U was probably pronounced “ow,” and y was more frequently used as a long I sound as in wine.
What remains one of the linguistic mysteries of all times is the not so gradual change in pronunciation from ME to Early Modern English. This is referred to as the Great Vowel Shift and occurred in approximately the late 15th century. Early Modern English changed vowel pronunciation to the more recognizable pronunciation of today’s British English, but why this occurred is still a matter of theory and speculation.