The /e/ vowel is here spelled <e>, <ea> in stead, <u> in bury and <ai> in said. The diphthong /ɪə/ is spelled <ear>, <ier> or <eer>, and <er> in era and peri.
This is a contrast bewteen a short front vowel and a front centering diphthong. It is not a specific problem for any known group of learners, though confusions may occur, especially before /r/ as in error/era.
The density value is low at 0.4%. The pairs make 26 semantic contrasts, giving a high loading of 79%.
bed beard bedded bearded bedding bearding beds beards berry beery bury beery cherry cheery Delhi dearly Des dears error era errors eras fed feared fez fears herring hearing herrings hearings lead leered Len lien lens liens Les leers Ned neared Nelly nearly perry peri pest pierced read reared res rears said seared says sears shed sheared sped speared stead steered wed weird wherry weary wherries wearies
Credit: John Higgins