1、er,ir,ur,通常读长音/ə:/.例如:term,her,girl,bird,nurse,hurt

2、or在/w/之后也读/ə:/.在其他情况下读/:/例如:word,worker,world,worm,afford,corn,horse

3、 er,ir,ur,or在非重读音节里读短元音/ə/,如:river,farmer,teacher,doctor.