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.
7、也可用but … too / as well替代not only … but also中的but also。例如：
She not only sang well but danced gracefully too（ or as well ）
8、也可以用besides，furthermore，moreover，in addition 等替代not only … but also 中的but also。例如：
Not only was there no food，but also （或furthermore，besides，moreover，in addition ）there was no water.
9、也可用merely，just，simply 等替代not only … but also 中的only。例如：
They not merely （ or just， simply ）broke into his office and stole his books but also tore up his manuscripts.
10、not only A but also B = B as well as A，但前者的强调重点在B ；后者的强调重点也在B。（汉译时，要先译 as well as 后面的词）例如：
The child is not only healthy but also lively. （= The child is lively as well as healthy. ）这孩子既健康又活泼。
It concerns not only me but also you. （= It concerns you as well as me. ）