ir stir 攪拌, 撥動 [Card #19; 字卡第19張: 第3個單字, 字母組合發音 ir]

R-controlled vowel；當母音後面跟著r，r會影響母音的發音（r會和母音成為一個音節，發不是長母音也不是短母音的特別音）。
Some more examples（更多 ir /ɝ/ 例字）：stir, sir, whir, fir, firm, affirm, confirm, infirm, third, bird, lovebird, dirt, dirty, flirt, shirt, undershirt, skirt, headfirst, first, thirst, thirsty, thirty, girl, swirl, twirl, whirl, girth, mirth, birth, birthday, irk, quirk, shirk, smirk, squirm, squirt, squirrel, circle, circular, circulate, circuit, circus, chirp, birch, virtue, virtual, girdle, circumvent, circumstance, infirmary