1 not only … but also … 不僅…也…是個平行結構，所以兩個詞後面的詞性要相同
I go swimming not only in summer, but also in winter. (名詞)
Summer in Taiwan is not only hot, but also humid. (形容詞)
Not only Sue works hard, but also Amber. (名詞) (可以放主詞前，後面的主詞的動詞因為相同可以省略)
2 放在動詞前面的時候，雖然有 not 這個否定詞，但是不加助動詞 do, did 等
He not only plays basketball, but also goes bowling. (動詞)
They not only saw a movie, but also had dinner. (動詞)
3 可以把 not only … but also … 放到句首倒裝來強調。句型是把 not only 放到句首，再加上助動詞，再加上主詞。Not only + auxiliary verb + Subject 。這個句型 but 可以省略。
Not only has he been to Europe, but he has also been to Africa.
= Not only has he been to Europe; he has also been to Africa.
Not only did she waste a lot of time, but she also spent a lot of money on mobile games.
4 通常 not only … but also … 用在寫作上，非正式口語比較不常見。比方說上面那一個例子，口語就會很簡單的說 She didn’t only waste a lot of time. She spent a lot of money too. 或者 She wasted a lot of time and spent a lot of money on mobile games.