A, letter that has stood at the head of the alphabet during the whole of the period through which it can be traced historically. This jack hartmanns alphabet a-z series for the letter aa. The first letter and first vowel of the modern english alphabet 2. How to use a in a sentence. Learn the letter a. learn that a is a vowel in the alphabet. A, or a, is the first letter and the first vowel letter of the latin alphabet, [1][2] used in the modern english alphabet, and others worldwide. Learn to recognize the … Any of several speech sounds represented by. The meaning of a is the 1st letter of the english alphabet.