PDE meaning in Regional ?

Modern English (sometimes New English or NE (ME) as opposed to Middle English and Old English) is the form of the English language spoken since the Great Vowel Shift in England, which began in the late 14th century and was completed in roughly 1550.

With some differences in vocabulary, texts from the early 17th century, such as the works of William Shakespeare and the King James Bible, are considered to be in Modern English, or more specifically, are referred to as using Early Modern English or Elizabethan English. English was adopted in regions around the world, such as North America, the Indian subcontinent, Africa, Australia and New Zealand through colonisation by the British Empire.

Modern English has many dialects spoken in many countries throughout the world, sometimes collectively referred to as the anglosphere. These dialects include American English, Australian English, British English (containing English English, Welsh English and Scottish English), Canadian English, Caribbean English, Hiberno-English, Indian English, Pakistani English, Nigerian English, New Zealand English, Philippine English, Singaporean English, and South African English.

According to the Ethnologue, there are almost 1 billion speakers of English as a first and second language. English is spoken as a first or a second language in many countries, with the most native speakers being in the United States, the United Kingdom, Australia, Canada, New Zealand and Ireland; there are also large populations in India, Pakistan, the Philippines and Southern Africa. It "has more non-native speakers than any other language, is more widely dispersed around the world and is used for more purposes than any other language". Its large number of speakers, plus its worldwide presence, have made English a common language ("lingua franca") "of the airlines, of the sea and shipping, of computer technology, of science and indeed of (global) communication generally".