as well as = 以及、此外 = in addition to/beside = not only but also。 一般來說 as well as 常常被拿來和 and 替換以避免一直重複使用 and。然而，事實上 as well as 的意思有強調其中一個比較物的意思。
基本用法
They like walking and skiing = 他們喜歡走路和滑雪。沒有強調走路或滑雪的簡單句型。
They like walking in addition to / beside / as well as skiing. = 他們喜歡走路，除了滑雪 = In addition to / beside / as well as skiing, they also like walking. = 除了滑雪，他們還喜歡走路。本句強調了「走路」，而輕視了「滑雪」。
注意到利用 prep + noun 可前移的特性，我們能讓句子的架構變成和中文習慣的順序相同，且此時應加 also，可以把這個 also 看成是中文的「還」。此外，這邊的 to 比較特別，它並非不定詞前的 to ，而是要接「名詞或動名詞」的那種介系詞 to。
They like not only skiing but (also) walking. = 他們不僅喜歡滑雪，更喜歡走路。注意 not only but also 強調的力道最大。在口說時 but also 與 walking 中間要稍斷，然後慢唸加重 walking 語氣。
She makes the cakes as well as / in addition to / beside the biscuits. = As well as / in addition to / beside the biscuits, she also makes the cakes. = She makes not only the biscuits but also the cakes. 與前述範例不同的地方，是本句用了名詞來當 make 的受語。
本句因為把 as well as 提到前面，所以要像 in addition to 一樣加個逗號。
Not only but also 進階用法
Not only do they like skiing but (also) walking. (not good) = Not only do they like skiing, but they also enjoy walking. (much better) 注意到 not only but also 的用法多變，尤其常常會出現倒裝句型（詳閱 → 倒裝句 inversion ←），本範例的前句文法正確然而卻無法傳達強調的感覺，常見必需如同後句一般，把主詞加回 also 前面，並順手把 like 變成 enjoy 這樣子更有力的字。這邊特別小心要把「逗號」加進去！因為當加回了主詞，but 後就變成一個完整的句子。
Not only does she make the biscuits but (also) the cakes. (not good) = Not only does she make the biscuits, but she is also a fantastic cake baker. (much better)。後句的用法更為複雜，首先把主詞加回 also 前面，接著改為用 be 動詞描述。這麼做看似沒有符合平行規則 (parallelism)，然而實則是利用 but 把兩個句子接起來了，所以才能有這樣子大的變動！
Not only is she a full-time student, but she also works as a fitness instructor. 本句前半使用 be 動，而後半則轉為一般動詞。
not only A but also B 主動詞一致
not only but also 似乎是「兩個」東西，感覺應該用複數動詞 => (X)。然而事實上 not only = in addition to 其句型強調 but also 後面的東西，並非是將兩個東西包成一組。所以動詞應按照 but 後面的主詞來判斷。
例如影片中的句子：This is gonna be a general challenge that not only the United States but also everybody is going to deal with. 看起來似乎包了兩個東西（美國和每個人），然而實際上重點是「每個人」，所以按文法來看，必需使用單數動詞。
還原字 + As Well As + Bare V
She needs to make the cakes as well as sell them. = As well as selling them, she needs to make the cakes. 因為 need to 的存在還原了後面的動詞，打破 as well as = in addition to 的規則。而前移 as well as 的話，則無需還原 sell。注意到這在文法上是極為特殊的狀況，沒有其他字出現類似的狀況。且記得，愈是常用的字，愈常出現特殊文法規則，所以請好好記住這個用法！
She can make cakes as well as sell them. 注意到因為 can 的存在還原了後面的動詞，打破 as well as = in addition to 的規則，也因此不能前移 as well as。
這個例句的 perform 是與 teach 相對，都是當作 enable him to 的補語，所以應使用原型。
本例句或許能解釋為什麼會有 as well as + 原型動詞的奇怪規則！上圖可看到 waste 是與 affect 相對（而不是與 teach 相對），因此仍使用 ing。如果使用原型 waste 的話，那意思就會很很搞笑，變成 her ability to 教學及浪費時間。
As well as = 和…一樣地好
She can make cakes as well as she sells them. = 她做蛋糕一樣地好和賣蛋糕相比。注意到本句 as well as 後面把主詞寫出來後 well 這個字變成在修飾 make，意思是「一樣地好」。
as (how well) I can (play).
As well as 當 and 使用
注意到 as well as 雖然意思和 and 差不多，但若使用 em dash 或者兩逗號的插入用法，那就一定要使用 as well as 才行。此外，所謂插入語就是拿掉也沒差的用語，所以動詞當然不可以把這個插入的東西考慮進來，所以可以看到例句使用了單數動詞 is。
可以發現本句 as well as 前面強調俱體的東西，而後面不想多說，所以模糊地講了 general 的東西。此外，與 and 連用也是本句的特色。
本句利用逗號進一步 de-emphasize 健康團體。其心理的 OS 是：「還有那個什麼來著，喔對了，健康團體」。在語氣上，也要停頓一下，做出那種順帶一提的感覺。
一個 as 的 well 用法
as well = too
as well = also
might as well = 不妨
just as well = 幸好 （idiom → Ref ←）
as well = 一樣好地。副詞 as 修副詞 well 修動詞 work