CLAUSES OF PURPOSE

1. The subject of the verb and the infinitive is always the same.

1.1. To+ base form

1.2. So as (not) to+ base form

1.3. in order (not) to+ base form

2. To express the porpuse or function of an item

2.1. For+ ing-form

3. Purpose with present or future time reference

3.1. So that+ subject+ can/may/will

4. Purpose with the past time reference

4.1. So that+ subject+ could/might/would

5. Purpose with the past time reference.

5.1. In case+ past tense

6. Purpose with pesent or future time reference

6.1. in case+present tense