1. not only … but also 应连接两个相对称的并列成分.例如：
Not only Mr Lin but also his son joined the Party two years ago. （连接两个主语）
I not only play tennis but also practise
shooting. （连接两个
谓语动词）
He plays not only the piano but also the violin.
（连接两个宾语）
They speak English not only in class but also in the dormitory. （连接两个地点状语）
注 1 ： She not only sings well but also dances
beautifully. = She doesn‘t only sing well but also dances beautifully.
注 2 ：句子 He not only plays the piano but also the violin 不是好的文体,因为 but
also 之后的成分与 not only 之后的成分不对称.
2. not only … but also 连接两个分句,并且 not
only 位于句首时,第一个分句中的主语和谓语要部分倒装.例如：
Not only does the sun give us light
but also it gives us heat.
Not only did he speak English correctly,
but also he speaks it fluently.
Not only is this young man clever but
also he is hardworking.
3. not only … but also 不能用在否定句中.例如：
误： They don‘t fear not only hardship but also death.
正： They fear neither hardship nor death.
正： They don‘t fear either hardship or
death.
4. not only … but also 连接两个主语时,谓语动词要和与其最近的主语保持人称和数的一致.例如：
Not only the students but also the teacher was against the plan. / Not only the teacher but also the students were against the plan.
5. not only … but also 中的 not only 不能分开使用,但 but also 却可以分开使用.例如：
The area was not only hit by an unexpected heavy rain, but some bridges were also washed
away.
6. not only … but also 连接两个并列成分时,可以省略 but 或 also ,也可以把 but also
都省略掉.例如：
I not only heard it but （ also ） saw it.
He was not only compelled to stay at home, （ but ） also forbidden to see his friend.
She not only finished the task ahead of time, （ but also ） she came to help us.