The F sound (IPA /f/) has four spellings. This irregularity makes it difficult for children to learn English spelling. These F-sound spellings are, F as in feet, PH as in physical, FF as in off and GH as in rough. Earlier I talked about PH. This week, I will cover FF and GH.
A few English words, and syllables, end with an FF making an F-sound /f/. The double-f spelling came from French and Latin. English words of French origin with this double-f spelling include*: buff (buffle), gaffe (gaffe) and stuff (estoffe). English words of Latin origin with this double-f spelling include*: affect (affectus), difficult (difficilis), effect (effectus) and office (officium).
This French double-f spelling started being used for many English words after the Norman French invasion of England in 1066.** Examples from Old English include*: cliff (clif), sniff (snofl) and staff (staf). The French/Latin double-f spelling was also used in English words borrowed from other languages*: bluff (Dutch: blaf), scuff (Old Norse: skufa), scruff (Frisian: skuft) and shroff*** (Hindi: saraf).
The double F is also at the end of many Eastern European names. When written in English, they are spelled with an -off or -ov ending. The suffix originally meant "son of" Examples include: Hrusoff and Romanoff.
In most English words the GH is silent. However, if GH is found at the end of a word it usually makes an F-sound. The only common (root) words where GH makes an F-sound are*: cough (coughen), enough (genog), laugh (hlihhan), rough (ruh), tough (toh), trough (trog) and slough (sluk: a snake removing it's skin). Note: The word slough (sloh) as a place name (a marsh or a town) pronounces -ough the same as the ow in cow. The Old English spellings of these words suggests that the GH was originally pronounced.
Of the strange F-sound spellings, PH is most commonly found at the beginning of words borrowed from Greek. Only a few common words use the FF spelling and then usually at the end of the word or syllable. The spelling GH is usually silent, but is still pronounced /f/ at the end of a few words. Knowing these patterns should help one guess at the correct spelling of words.
There are a great many PH-containing suffixes and prefixes in scientific and medical English. Later I will survey some of the more common examples.
* For simplicity the original Old English/French or other ancient spelling is in brackets.
** An exception to this pattern is the word off which is the emphatic adverbial Old English version of the word of.
*** The word shroff is Asian and Hong Kong English and not normally used in the UK or US.