not onlybut also主謂一致

1、not only … but also應連接兩個相對稱的並列成分。例如：

Not only MrLin but also his son joined the Party two years ago.不僅是林先生，他的兒子也在兩年前加入了該黨。(連接兩主語)

He plays not only the piano but also the violin.他不僅彈鋼琴，還拉小提琴。(連接兩個賓語)

注：句子 He not only plays the piano but also the violin 不是好的文體，因為 but also 之後的成分與 not only 之後的成分不對稱.

2、not only …but also 連接兩個分句，並且 not only /until位於句首時，第一個分句中的主語和謂語要部分倒裝。例如：

Not only does the sun give us light but also it gives us heat.太陽不僅給了我們光明，也給了我們熱量。

Not only didhe speak English correctly，but also he speaks it fluently.他不僅講正確的英語，而且講得很流利