Most often, the /p/ sound in the initial, final, and medial positions is made by the consonant p as represented by words such as pet, tap, or ape. The use of the consonant p is very consistent for this sound, although there are exceptions. Sometimes the consonant p is silent, for example, when it is the second p in words like supper and dipper. It is also silent when followed by n, s, or t in words like pneumonia, psychology, and pterodactyl. When followed by the letter h, the combination makes an /f/ sound as in phone and phase.