8.3The Great Vowel Shift

The transition from Middle English to Modern English was marked by a major change in the pronunciation of vowels during the 15th and 16th centuries. This change, termed the Great Vowel Shift by the Danish linguist Otto Jespersen, consisted of a shift in the articulation of vowels with respect to the positions assumed by the tongue and the lips. The Great Vowel Shift changed the pronunciation of 18 of the 20 distinctive vowels and diphthongs of Middle English. Spelling, however, remained unchanged and was preserved from then on as a result of the advent of printing in England in about 1475, during the shift. (In general, Middle English orthography was much more phonetic than Modern English; all consonants, for example, were pronounced, whereas now letters such as the l preserved in walking are silent).

All long vowels, with the exception of /i:/ (pronounced in Middle English somewhat like ee in need) and /u:/ (pronounced in Middle English like oo in food), came to be pronounced with the jaw position one degree higher. Pronounced previously in the highest possible position, the/i:/ became diphthongized to “ah-ee”, and the/u:/ to “ee-oo”. The Great Vowel Shift, which is still in progress, caused the pronunciation in English of the letters a, e, i, o, and u to differ from that used in most other languages of Western Europe. The approximate date when words were borrowed from other languages can be ascertained by means of these and other sound changes. Thus it is known that the old French word dame was borrowed before the shift, since its vowel shifted with the Middle English /e:/ from a pronunciation like that of the vowel in calm to that of the vowel in name.