er音标是什么

1.[ə]中元音，口形与唇成自然状，肌肉放松，口腔半开，发音时舌头中部最高，短元音。如单词:ago about asleep above again among mother brother doctor teacher never danger sugar order butter picture 2.[3:]平舌音，是由旧国际音标中的[ə:]改过来的,发音规则:口腔在半开状态，唇向两边咧开，舌头平放,长元音。如单词:girl shirt hurt burn bird nurse work worm curse world dirty skirt thirsty worst person curtin serve early