The New Student's Reference Work/P

P (pē), the sixteenth letter, is a voiceless consonant.  It is articulated at the lips, and is called a sharp labial, as in cup,pea, spy.  Initial p before n, sh, s and t is silent, as in pneumatic, psalm, pshaw, ptarmigan.  P also is silent in accompt, corps, raspberry, receipt, sempstress.  No native English word begins with pn, ps or pt.