The /f/ sound is spelled with <f>, <ff>, or <ph> in graph. The /v/ sound is spelled <v>, or <ve>. Notice the silent <l> in calve and halve. The homograph grave occurs here meaning a French accent and contrasted with graph.
The contrast is between two labio-dental fricatives, one voiceless and one voiced. The distinction is often used to distinguish noun from verb as in half/halve or shelf/shelve. This may be a problem for German and Dutch learners since those languages do not have a final /v/. The sounds are in any case similar enough to lead to slips of the ear even among native speakers.
Interesting pairs include:
The mean density value is 3.1%. The list makes 91 semantic distinctions, a loading of 59%.
belief believe brief breve briefs breves calf calve confection convection defied divide defies devise define divine defined divined defines divines defining divining deafen Devon disbelief disbelieve elfish elvish fairy vary fairies varies fail vale fails vales fail veil failed veiled failing veiling fails veils fain vain fain vein fain vane falter vaulter falters vaulters fan van fans vans fast vast fastness vastness fat vat fats vats fault vault faulted vaulted faulting vaulting faults vaults fear veer feared veered fearing veering fears veers fee V fees V's feign vain feign vane feigns vanes feign vein feigns veins feigned veined feigns veins felt veld fend vend fended vended fending vending fends vends fender vender fenders venders ferry very fetch vetch fetches vetches fetid vetted feud viewed few view fewer viewer fie vie Fife five figure vigour file vile file vial files vials fine vine fines vines finery vinery first versed fiver viva fivers vivas fizz viz foal vole foals voles focal vocal foil voile foist voiced folly volley follies volleys fox vox fuse views graph grave grief grieve half halve infantry inventory infantries inventories infest invest infested invested infesting investing infests invests leaf leave leafing leaving life live loofah louvre loofahs louvres love luff loving luffing NAAFI navvy off of phial vile phial vial phials vials plaintiff plaintive proof prove proofing proving raffish ravish reef reeve ref Rev. reference reverence referential reverential refuse reviews relief relieve reproof reprove rife rive rifle rival rifled rivalled rifles rivals rifling rivalling safe save safes saves safer saver safer savour scurfy scurvy serf serve shelf shelve shovel shuffle shovelled shuffled shovels shuffles sniffle snivel sniffled snivelled sniffles snivels sniffling snivelling staff starve staffing starving staffs starves strife strive surf serve surfing serving surface service surfaced serviced surfaces services surfacing servicing thief thieve wafer waiver wafers waivers waif waive waifs waives wife wive
John Higgins, Shaftesbury, October 2010.