wail和sob的区别主要在于含义及用法上。wail可做名词和动词，含义为“哀号”、“大声呼叫”、“呼啸”、“号啕”、“高声抱怨”；sob也可作名词和动词，含义为“抽噎”、“哭诉”、“抽噎声”、“呜咽声”。

wail可作名词和动词，意为哀号;(因悲伤或疼痛)哭号，恸哭;大声呼叫;高声抱怨;发出长而高的声音;呼啸；(疼痛或悲伤时发出的)号啕，哀号。

例句：The little girl was wailing miserably.

那小女孩难过得号啕大哭。

There's no point wailing about something that happened so long ago.

事情早已发生，痛哭流涕也于事无补。

Ambulances raced by with sirens wailing.

救护车高声鸣笛疾驰而过。

The women began to wail in mourning.

女人们开始哀哭起来。

Police cars, their sirens wailing, accompanied the lorries...

警车护送着大卡车，一路警笛长鸣。

Many wailed and screamed.

紧闭的窗户外狂风呼啸。

The wind wailed outside the closed windows.

许多人号啕着，尖叫着。

The siren, which had stopped briefly, wailed again.

刚刚停了不久的警号又呼啸起来。

sob主要用作名词和动词，意为抽噎;啜泣;呜咽;哭诉;泣诉;抽噎着说；抽噎(声);啜泣(声);呜咽(声)。

例句：He started to sob uncontrollably.

他不由自主地抽噎起来。

He sobbed out his troubles.

他哭着述说了自己的烦恼。

He gave a deep sob.

他发出一声低沉的抽噎声。

She began to sob again, burying her face in the pillow...

她把脸埋在枕头里，又开始抽噎起来。

His sobs soon turned to sniffs.

不多时，他的呜咽变成了啜泣。

All we could hear were loud sobs, but no articulate words.

我们听到的只是大声啜泣，没有清楚的话语。

She didn't want to die, and she was sobbing.

她不想死，她在啜泣。