Perhaps the most noticeable of these differences is in the vowel sound in such words as fast, path, grass, dance, can’t, half. At the end of the eighteenth century southern England began to change from what is called a flat a to a broad a in these words, that is from a sound like the a in man to one like the a in father. The change affected words in which the vowel occurred before f, sk, sp, st, ss, th, and n followed by certain consonants. In parts of New England the same change took place, but in most other parts of the country the old sound was preserved, and fast, path, etc., are pronounced with the vowel of pan. In some speakers there is a tendency to employ an intermediate vowel, halfway between the a of pan and father, but the “flat a” must be regarded as the typical American pronunciation. Next to the retention of the flat a, another distinction which is less apparent to normal people is the pronunciation of the o in such words as not, lot, hot, top. In England this is still an open o pronounced with the lips rounded, but is American except in parts of New England it has commonly lost its rounding and in most words has become a sound identical in quality with the a in father, only short. The differences of vowel sounds are shown with examples in the table below.