Pronunciation of English ⟨a⟩

There are a variety of pronunciations in modern English and in historical forms of the language for words spelled with the letter ⟨a⟩. Most of these go back to the low vowel (the "short A") of earlier Middle English, which later developed both long and short forms. The sound of the long vowel was altered in the Great Vowel Shift, but later a new long A (or "broad A") developed which was not subject to the shift. These processes have produced the main four pronunciations of ⟨a⟩ in present-day English: those found in the words trap, face, father and square (with the phonetic output depending on whether the dialect is rhotic or not, and, in rhotic dialects, whether or not the Mary-merry merger occurs). Separate developments have produced additional pronunciations in words like wash, talk and comma.