Unit 8.1

Clauses of Purpose


A clause of purpose is a clause expressing purpose and reason linked to the principal through expressions of purpose.


There are two structures for the clauses of purpose, they differ in the order of words but not in the meaning.

The structure is:
Clause 1 + Purpose expression + Clause2;
Purpose expression + Clause + (,) + Clause

The most commonly used expressions of purpose are: in order to, so as to, so that, to

  • We place in order to and to between two clauses or at the beginning of the clauses.
  • We place so as to and so that can only be placed between two clauses.


  • I am learning to drive in order to be more independent.
  • In order to avoid an accident, we had to stop.
  • I am going to Africa to go on a safari.
  • To learn how to ride a bike, he is going to take lessons.
  • I bought a tent so as to go camping.
  • I worked hard so as to succeed.
  • Let’s make plans together so that we can travel as a family.
  • They talked to him so that he could know the truth. 


We use in order to, so as to, so that, to … to introduce the purpose of the sentence. In this way we can understand the reason behind the other sentence.


We use expressions of purpose to express the reason why something exists, is done or used. A sentence containing these expressions is usually composed by two clauses linked by the expressions of purpose.

The structure is: a clause followed by a purpose expression and another clause (we do not use a comma here). We can also start with a purpose expression followed by a clause, a comma and another clause.

The most commonly used expressions of purpose are: in order to, so as to, so that, to

For example:
— “I have to study in order to be successful.” = I need to study because I want to be successful.
— “To become rich, my dad worked too hard.” = The reason why my dad worked hard was that he wanted to be rich.

Let’s revise this content within the {Form} section. Take a look at the {Example} section that shows its use within a context.