Decoding the letter P

The letter P, lowercase p (pronounced /piː/) very reliably represents IPA phoneme /p/. For examples see IPA phoneme /p/.

"ph"

 * normally as /f/: atmosphere - Christopher - emphasis - Joseph - paragraph - phase - phenomenon - Philippines - philosophy - phone - photograph -   telephone
 * as /v/: nephew /ˈnefjuː, ˈnevjuː/, Stephen
 * as /ph/ in compound words: loophole, uphill
 * silent "h": shepherd /ˈʃepərd/

Silent "p"
Exceptionally "p" can be silent.
 * cupboard, pneumonia, psychology, pterodactyl, raspberry, receipt

Homophones

 * Stephen - Steven
 * shepherd - Sheppard - Shepard