Some conjunctions are used in pairs. They are called correlative conjunctions. Most of these are of the coordinating type.

Either …or

• You must either follow my instructions or resign.
• He is either a fool or a madman.
• Either you or he will have to go.
• Either you will leave this house or I will call the police.
• I don’t speak either French or German.

We use either…or to talk about a choice between two possibilities (and sometimes more than two).

• If you want ice-cream you can have either chocolate, vanilla or strawberry.

Neither … nor

• I will neither follow your instructions nor resign.
• He is neither a fool nor a madman.
• I neither smoke nor drink.

We use neither … nor to join two negative ideas. It is the opposite of both…and. Sometimes more than two ideas are connected by neither…nor.

• He neither smiled, spoke, nor looked at me.

Not only…but also

• They not only looted the shop, but also set fire to it.
• Not only John, but Peter also got a prize.
• He visited not only France but also Germany.
• She not only plays the piano, but also the violin.

Also is often omitted.

• He was not only brave but prudent.

Note that in informal English not only…but also is not very common; other structures are generally preferred.

• She doesn’t only play the piano. She plays the violin too.

Not…but

• The culprit was not John but Peter.
• He did not stop the car but drove on.
• It is not the best but reasonably good.

Whether…or

• I don’t know whether I should stay or leave.
• Whether he comes or not makes no difference.

Both…and

• She is both clever and pretty.
• He is both scholarly and cultured.
• Both John and Peter spoke at the meeting.

As/so…as

• He is not as/so bad as many think.
• She is not as/so successful as her sister.
• The situation is not as/so difficult as people make out.

So… that

• The task is so difficult that one man alone can’t do it.
• The officer was so inefficient that he had to be sacked.

Such…that

• I have such regard for him that I will do anything to please him.
• Such was her beauty that princes from far and near came to woo her.

Such…as

• I gave him such help as I could.
• You must give such an assurance as will satisfy people.
• Such valuables as she left were sold at an auction.

Note that it is wrong to use that instead of as in these sentences.