The /əʊ/ diphthong is spelled in many ways including <oCe>, <oe>, <oa>, <ow>, <eau> in beau, and occurs in the letter name O. The /ɪə/ diphthong is spelled <ear>, <eer> or <ie>, and <eir> in weir.
This is a contrast between two diphthongs with different starting positions and direction of movement. It is not a problem for any learner.
Interesting pairs include:
corrode careered
oppose appears
Perhaps the best-known appearance of one of these pairs is in the song in My Fair Lady, "Doe a deer, a female deer".
The density figure is 1.91%. The set makes 44 semantic contrasts giving a loading of 57.1%.
arose arrears beau beer beaux beers beau bier beaux biers bow beer bows beers bow bier bows biers bode beard boded bearded bodes beards boding bearding chose cheers close clears corrode careered doe dear does dears doe deer dough dear dough deer foe fear foes fears go gear goes gears goad geared hoe hear hoes hears know near knows nears load leered loan lien loans liens low leer lows leers mow mere mows meres no near node neared oppose appears O ear O's ears pose peers post pierced rôle real road reared roe rhea roes rheas roe rear roes rears rose rears sew sear sewed seared sews sears so sear sow sear sowed seared sows sears show shear showed sheared shows shears show sheer sow sneer snowed sneered snows sneers Spode speared stow steer stowed steered stows steers toe tear toes tears tow tear tows tears unroll unreal woad weird woe weir woes weirs
John Higgins, Shaftesbury, December 2009