Purpose clause

Definition

A purpose clause explains the aim or intended result of an action. Finite purpose clauses commonly use so that or in order that, often with a modal such as can, could, will, would, may, or might.

Examples

• I left early so that I could catch the train.

  The clause explains the purpose of leaving early.

• Speak clearly so that everyone can hear.

  The purpose clause has its own subject, everyone.

• The details were removed in order that the report might remain confidential.

  In order that is a more formal purpose linker.

Purpose clause vs. purpose phrase

A finite purpose clause contains its own subject and finite verb. A purpose infinitive normally shares the main clause's subject.

Negative purpose uses so that ... not or to avoid

To express prevention, a finite clause can use so that ... not, while a non-finite alternative often uses in order not to, so as not to, or to avoid + -ing.

• We whispered so that the baby would not wake up.

  The clause states the intended prevention.

• We whispered to avoid waking the baby.

  The non-finite phrase gives the same broad purpose.

Common mistakes