as well與as well as只有一詞之差，但意義和用法卻相差甚遠。
一、as well 用法：
1、as well常用作狀語，作“又；也”解，相當于too或also，常位于句末，無須用逗號與句子分開。如：
I am going to London and my sister is going as well（＝going，too）.
我要到倫敦去，我妹妹也要去。
I not only play the guitar，I sing as well（＝I also sing ）.
我不但彈吉他，而且還演唱。
2、as well 在口語中也可用于句中，作“也好，也行”或“倒不如”解，用來緩和語氣。如：
You may as well go.
你去也好。
The weather was so bad that we might（just）as well have stayed at home.
天氣太壞了，早知道如此，倒不如呆在家里為好。
3、as well 可以直接用于just后，用作應答語（可視為It's just as well、的省略），作“幸虧，幸而；無妨；沒關系”解。如：
—We were too late to see the film.
我們去得太晚了，沒有看上電影。
—Just as well、I hear it isn't very good.
不必遺憾，我聽說電影也不怎么樣。
二、as well as 用法
1、as well as常用來連接兩個并列的成分，如名詞、形容詞、動詞、介詞，通常不位于句首。作“也，還”解。它強調的是前一項，后一項只是順便提及。因此連接并列主語時，謂語動詞與前一項一致；翻譯時要先譯后面，再譯前面。而用not only …but also…連接時，謂語動詞與后一項一致。如：
Your wife as well as you is friendly to me.
不僅你而且你的妻子也對我很友好。
（＝Not only you but also your wife is friendly to me、）
Electric energy can be changed into light energy as well as into sound energy.
電能既可以被轉變成聲能，又可以被轉變成光能。
2、as well as 用來表示同級比較，指“一樣好”。如：
You look as well as you did ten years ago.
你的身體看起來還和十年前一樣好。
He plays the guitar as well as you.
他的吉他彈得和你一樣好。
3、用作介詞此時，as well as相當于besides，in addition to，意思為“除……之外”，后面通常接名詞或動詞，尤其是位于句首時。As well as / Besides / In addition to eating five course meals, they drank seven bottles of wine. 除了五道菜外，他們還喝了七瓶酒。