The /eɪ/ diphthong is spelled <aCe>, <ai>, <ay> or <ei> in neigh, and occurs in the letter names A and J. The /ɪə/ diphthong is spelled <eer>, <ear>, <ere> or <ier>, and <eir> in weird.
This is a contrast between two diphthongs. The starting positions are similar but the direction of movement is different. It is not a problem for learners.
Interesting pairs include:
arrays arrears
The density figure is 1.91%. The set makes 53 semantic contrasts giving a loading of 68.8%.
A ear A's ears amaze ameers arrays arrears baize beers bay beer bays beers bay bier bays biers bayed beard bey beer beys beers bey bier beys biers daily dearly day dear days dears day deer face fierce facer fiercer fade feared gay gear gays gears hay hear hay here haze hears J jeer J's jeers jade jeered lain lien lane lien lanes liens lay leer lays leers may mere Mays meres nay near neigh near neighed neared neighs nears pace pierce paced pierced paces pierces pacing piercing pay peer paid peered pays peers pay pier pays piers phase fears raid reared rail real raise rears raise rheas ray rear rays rears ray rhea rays rheas shade sheared spade speared spay spear spays spears staid steered stay steer stays steers talus tearless wade weird wader weirder way weir ways weirs weigh weir weighs weirs weighed weird
John Higgins, Shaftesbury, December 2009