The /3/ vowel is spelled with <er>, <ir>, <ear>, <ur>, <our> in tourney and <or> in worldly. The /aɪ/ vowel is spelled <iCe>, <igh> or <y>, and is seen in the letter names I and Y. Notice how the homograph insert turns up in two different pairs with different stress patterns, insert/incite and insert/insight.
This is a contrast between a long vowel and a diphthong. The starting positions are fairly close but it does not seem to be a problem for learners.
Interesting pairs include:
concern consign
fervour fiver
turtle title
The density figure is 5.68%. The set makes 89 semantic contrasts giving a loading of 50.8%.
alert alight alerted alighted alerting alighting alerts alights Bert bight Bert bight bird bide birds bides blurt blight blurted blighted blurting blighting blurts blights burble Bible burbles Bibles burke bike burked biked burkes bikes burking biking burn bine burns bines burned bind burr buy burrs buys burr by burr bye burrs byes cert cite certs cites cert sight certs sights cert site certs sites churn chine churns chines circle cycle circled cycled circles cycles circling cycling concern consign concerned consigned concerning consigning concerns consigns conferred confide cowherd cowhide cowherds cowhides curt kite defer defy deferred defied defers defies demurs demise derv dive dirk dike dirks dikes durst diced earl I'll earl aisle earls aisles earl isle earls isles err I erred I'd errs I's Erse ice fern fine ferns fines fervour fiver flirt flight flirted flighted flirting flighting flirts flights furl file furled filed furling filing furls files gird guide girded guided girding guiding girds guides girl guile heard hide herd hide herding hiding herds hides her hi her high hers hies hertz heights hurt height insert incite inserted incited inserting inciting inserts incites insert insight inserts insights invert invite inverted invited inverting inviting inverts invites learn line learned lined learning lining learns lines learner liner learners liners long-term long-time lurk like lurked liked lurking liking lurks likes murk Mike nerves knives nurse nice pearl pile pearled piled pearling piling pearls piles perk pike perks pikes purr pi purr pie purrs pies purred pied sermon Simon Shirley shyly sir sigh sirs sighs slur sly slurred slide spirt spite spirted spited spirting spiting spirts spites spurn spine spurns spines spurred spied spur spy spurs spies Stirling styling stir sty stirs sties surd side surds sides term time termed timed terming timing terms times tern tine terns tines tourney tiny Turk tike Turks tikes turn tine turned tined turns tines turps types turtle title turtles titles ugh I verb vibe verbs vibes verse vice verses vices were why were Y wert Wight wert white whirl while whirled whiled whirling whiling whirls whiles whirr why whirred wide whirr Y whirrs Y's worldly wildly