Purpose clauses: explain why

A purpose clause answers a practical question: What did someone do this for? Look at the intended result rather than only at the first action. If the second action is the goal, you can choose a purpose expression.

Ravi called the clinic to make an appointment.

Making an appointment is Ravi's goal in calling. The infinitive to make names that goal.

What is the purpose in 'Hana wore boots to walk through the snow'?

Her purpose is to walk through the snow. Wearing boots helps Hana do that action.

Use to plus a base verb when the person or group in the main clause also does the purpose action. This is the most common short pattern for explaining a goal.

I opened the document to check the date.

I is the subject of opened and check. After to, use the base verb check, not checked or checking.

They practiced the conversation to feel more confident.

They practiced because they wanted to feel more confident. To plus feel gives the purpose in a shorter form.

Complete the sentence: 'We stopped at the shop ___ buy water.'

Use to: 'We stopped at the shop to buy water.' The group stopped and the group will buy the water.

In order to also comes before a base verb. It does not change the main grammar rule. It can suit formal instructions, reports, or a careful explanation, while to is usually more natural in a quick conversation.

Please show your ticket in order to enter the building.

The person with the ticket is also the person who enters, so in order to enter follows the same-subject pattern.

The report lists the steps in order to make the process clear.

To make the process clear is also correct. In order to gives the sentence a more formal tone.

Which verb form follows in order to: a base verb, a past verb, or an -ing form?

Use a base verb: 'in order to enter,' 'in order to check,' or 'in order to understand.'

Use so that when the purpose needs its own subject and verb. This is useful when one person acts to help another person, or when you want to include can, could, will, or would.

I wrote the instructions down so that my neighbor could use them later.

My neighbor is the subject after so that, and could use is the verb phrase. A short to phrase cannot include that separate subject.

The guide repeated the number so that everyone could hear it.

Everyone has a different role from the guide, so the full clause makes the relationship clear.

Choose the better form: 'I moved the chair so that my guest could sit' or 'I moved the chair to my guest could sit'?

Use 'so that my guest could sit.' The clause has its own subject, my guest, and the modal verb could.

Sometimes the goal is to prevent a problem. Use so that plus a negative clause when you need a subject or modal verb. Use in order not to plus a base verb when the subject stays the same.

Amir spoke quietly so that he would not wake the baby.

The words would not wake show the unwanted result Amir wants to prevent.

Amir spoke quietly in order not to wake the baby.

Amir is the subject of both spoke and wake, so in order not to wake is possible.

Complete the sentence: 'I set a reminder so that I ___ forget the deadline.'

Use would not or do not, depending on the time you mean. For a past plan, say 'so that I would not forget the deadline.'

A purpose is an intended result. A cause is a reason that already exists. Compare the meaning before you choose to, so that, or because. The same first action can have either relationship.

Ella closed the door to reduce the noise.

Reducing the noise is Ella's goal, so to reduce expresses purpose.

Ella closed the door because the noise was distracting.

The distracting noise is the cause of her action. Because introduces that existing reason.

Which word shows purpose in 'Noah took a map because the roads were unfamiliar'?

None of the words shows purpose. Because explains the cause. To show Noah's goal, you could say 'Noah took a map to find the address.'