The Mutt and the Bug
The letter u makes several sounds. The most common representation of the short /u/ vowel sound is in words where the vowel is in a closed pattern, as in cut, hug, bus, duck, and truck. It also appears in the initial position in words like up. There are other ways to represent the short /u/ vowel sound, such as the o in son, ou in double, and oo in flood.