The /v/ sound is spelled with <v>, <ve> or <vv> in civvy. The /s/ sound is spelled <s>, <ss>, <c>, or <ps> in pseud. Notice how verve makes pairs with verse and serve, and how the homograph grave makes pairs with grace and grass.
The contrast is between a voiced labio-dental fricative and a voiceless alveolar fricative. It is not a problem for learners.
Interesting pairs include:
civilian Sicilian
clavicle classical
havoc hassock
louvre looser
validity solidity
vindicate syndicate
volleyed solid
voluble soluble
The mean density value is 1.4%. The list makes 125 semantic distinctions, a loading of 53%.
avail assail availed assailed availing assailing avails assails available assailable Ave ass aversion assertion aversions assertions avert assert averted asserted averting asserting averts asserts avid acid avidity acidity bevy Bessie brave brace braving bracing braved braced cave case caved cased caving casing cavil Kassel civilian Sicilian civilians Sicilians civvy sissy civvies sissies clavicle classical clove close clover closer convert concert converted concerted converting concerting converts concerts coveys cusses curve curse curving cursing curved cursed Dave dace deceive decease deceiving deceasing deceived deceased Denver denser dive dice diving dicing dived diced divide decide divided decided divides decides dividing deciding division decision divisions decisions divisive decisive favour facer favours facers grave grace grave grass grieve grease grieving greasing grieved greased grieve Greece grove gross haven hasten havens hastens havoc hassock inventive incentive inversion insertion inversions insertions invert insert inverted inserted inverting inserting inverts inserts invidious insidious invidiously insidiously invite incite invited incited invites incites inviting inciting invite insight invites insights I've ice ivies ices Ivy icy lav lass lave lace laving lacing leave lease leaving leasing leaven lessen leavened lessened leavening lessening leavens lessens live lice louvre looser move moose movies mooses nerve nurse nerving nursing nerved nursed Neville nestle outvied outside pave pace paving pacing peeve peace peeve piece peeving piecing qv QC rave race raving racing raved raced raver racer ravers racers relieve release relieving releasing relieved released rive rice thrive thrice unavailable unassailable undivided undecided V C V's C's vac sac vacs sacks vain sane vainer saner vainest sanest vainly sanely vale sail vale sails vale sale vales sales valid sallied validity solidity valley sally valleys sallies valve salve valves salves van san vans sans Vandal sandal Vandals sandals vane sane vane seine vanes seines vanity sanity vat sat vault salt vaulted salted vaulting salting vaults salts vaulter psalter vaulters psalters vaunter saunter vaunters saunters VC cc VD CD vector sector vectors sectors veer sear veered seared veering searing veers sears veil sail veiled sailed veiling sailing veils sails veil sale veils sales vein sane vein seine veined seined veins seines vend send vending sending vends sends vendor sender vendors senders vent cent vents cents vent scent vents scents vented scented venting scenting vent sent ventral central verge surge verged surged verges surges verging surging verve serve verve verse vet set vets sets vetting setting vex secs vex sex vexed sexed vexes sexes vexing sexing vie sigh vying sighing vied sighed vies sighs vied side Vienna sienna vies size view sue viewing suing views sues viewed sued viewed pseud viewer sewer viewers sewers villa Scylla Vince since vindicate syndicate vindicated syndicated vindicates syndicates vindicating syndicating vindication syndication vindications syndications vine sign vines signs vine sine vinous sinus vista sister vistas sisters vivid viscid voile soil vol Sol vole sole voles soles volleyed solid voluble soluble volubility solubility vow sow vows sows vox socks VP cp you've use