一、在形容词词尾直接加-ly.

　　如:real-really;helpful-helpfully;careful-carefully;hopeful-hopefully;slow-slowly;quick-quickly;quiet-quietly

　　二、以辅音字母加y结尾的形容词要变y为i,然后再加-ly.

　　如:busy-busily;angry-angrily;easy-easily

　　三、某些以辅音字母加不发音的字母e结尾和以-ue结尾的形容词要先去掉e,然后再加-y或-ly.如:terrible-terribly;true-truly;gentle-gently

　　另外,副词还可以由形容词加前缀a-得来,如:loud(adj.)-aloud(adv.)

　　此外,部分名词加后缀也可变成副词,如:part-partly.

　　例句:Itispartlyherfault.有部分是她的错.

　　需注意:friendly;motherly;lovely等词是形容词而非副词.