Not only … but also … 與 “both … and …”、”neither … nor …”、”either … or …” 等一樣，在英文中叫做相關字組 (correlatives) 或相關連接詞 (correlative conjunctions)。它們的用法特色是，與其兩個元素連用的詞類和結構必須平行對稱、對仗工整。
Not only … but also … (不僅…而且…；不但…而且…) 係用在正式的上下文中。例如：
- The war caused not only destruction and death but also generations of hatred between the two countries. (戰爭不僅造成了破壞和死亡，也造成了兩個國家之間代代相傳的仇恨)
- The car not only is economical but also feels good to drive. (這部車不僅省油，而且駕駛感良好)
- This investigation is not only one that is continuing and worldwide but also one that we expect to continue for quite some time. (這項調查不僅是一項在全球範圍內持續進行的調查，而且也是一項我們預計將持續相當長一段時間的調查)