In English orthography and most other European languages, ⟨p⟩ represents the sound /p/.
A common digraph in English is ⟨ph⟩, which represents the sound , and can be used to transliterate ⟨φ⟩ phi in loanwords from Greek. In German, the digraph ⟨pf⟩ is common, representing a labial affricate /pf/.
Most English words beginning with ⟨p⟩ are of foreign origin, primarily French, Latin and Greek; these languages preserve Proto-Indo-European initial *p. Native English cognates of such words often start with ⟨f⟩, since English is a Germanic language and thus has undergone Grimm's law; a native English word with initial /p/ would reflect Proto-Indo-European initial *b, which is so rare that its existence as a phoneme is disputed. However, native English words with non-initial ⟨p⟩ are quite common; such words can come from either Kluge's law or the consonant cluster /sp/ (PIE *p has been preserved after s).
In the International Phonetic Alphabet, /p/ is used to represent the voiceless bilabial plosive.
