Grammar B1 Subordinating Conjunctions

So that vs in order to — purpose clauses

So that vs in order to — purpose clauses

The Key Difference

Both 'so that' and 'in order to' express purpose — they explain why someone does something. However, they have different structures. 'In order to' is followed by an infinitive verb (base form). 'So that' is followed by a complete clause with a subject and a conjugated verb. Understanding when to use each one will help you write clearer sentences.

Structure Comparison

'In order to' requires: [Subject] + [in order to] + [infinitive verb]. 'So that' requires: [Subject] + [verb] + [so that] + [subject] + [can/will/would] + [verb]. Use 'in order to' when the subject is the same for both actions. Use 'so that' when you want to emphasize result or when the subjects are different.

So That vs In Order To: Side-by-Side Comparison

Feature So That In Order To
Form So that + subject + modal/auxiliary verb (can, could, will, would, may, might) + base verb In order to + base infinitive verb (no additional subject needed)
Subject Requirement Requires its own subject in the clause, which can differ from the main clause subject (e.g. I spoke slowly so that she could understand) No separate subject; the subject of in order to must match the main clause subject (e.g. I spoke slowly in order to be understood)
Formality Level Neutral to informal; suitable in both spoken and written English Slightly more formal; common in academic, professional, or written contexts; to alone is an informal equivalent
When to Use Use when the purpose involves a different subject, when using modals (can, will, would, etc.), or when expressing a result or desired outcome for another person or thing Use when the subject of the main clause performs the action for their own purpose; interchangeable with a plain infinitive (to) in most contexts
Positive Example She saved money so that she could buy a new laptop.

He turned up the volume so that everyone could hear the announcement.
She saved money in order to buy a new laptop.

He turned up the volume in order to hear the announcement clearly.
Negative Example She whispered so that the baby would not wake up.

He left early so that he wouldn't miss the train.
She whispered in order not to wake the baby.

He left early in order not to miss the train.

⚠️ Note: negation is in order not to, not in order to not
Typical Clause Position Usually placed after the main clause; placing it at the start of a sentence is rare and can sound awkward Can appear before or after the main clause: In order to pass the exam, she studied every day.
Tense Flexibility Verb tense in the so that clause shifts with the main verb tense:
• Present → can / may
• Past → could / might / would
Always uses the base infinitive regardless of the main clause tense; no tense adjustment needed
Key Signal Words / Variants So that, in order that (more formal written variant of so that), such that In order to, to (plain infinitive), so as to (formal alternative), with the aim of + gerund
Common Mistakes She left early so that catch the bus. (missing subject + modal)
She left early so that she could catch the bus.
I called him in order to he could know. (cannot add a different subject)
I called him so that he could know.
🔑 Key Difference: The core distinction is about subjects and structure. Use so that when the purpose clause has its own subject (especially a different one from the main clause) and needs a modal verb. Use in order to when both clauses share the same subject and a plain infinitive follows — it is essentially a more emphatic or formal version of a simple infinitive of purpose (to). When in doubt: if you can replace your phrase with just to + verb without changing the meaning, in order to is the right choice; if you need a new subject and a modal, choose so that.
Formula
✔ Positive
Subject + verb + in order to + infinitive verb
I go to the gym in order to stay healthy.

Examples

I studied hard in order to pass the exam.
I studied hard in order to pass the exam.
Same subject (I) · Purpose clause
She wakes up early in order to exercise before work.
She wakes up early in order to exercise before work.
Routine action · Same subject
We saved money in order to buy a new laptop.
We saved money in order to buy a new laptop.
Long-term goal · Infinitive form
I left early so that I would not miss the train.
I left early so that I would not miss the train.
Same subject · Emphasizes result
My teacher explained it slowly so that all students could understand.
My teacher explained it slowly so that all students could understand.
Different subjects · Result-focused
Turn down the volume so that the baby can sleep.
Turn down the volume so that the baby can sleep.
Different subjects · Request/instruction
When to use it
Explaining Personal Goals
Use 'in order to' for clear, direct statements about why you do something for yourself.
"I'm learning English in order to get a better job."
Helping Others Achieve Results
Use 'so that' when someone does something to benefit another person or group.
"The teacher repeated the lesson so that everyone could understand."
Formal or Written Instructions
Both are acceptable, but 'in order to' is more common in formal writing and instructions.
"Press button A in order to activate the device."
Signal words
purpose reason why goal objective can will would may might
Common Mistakes
Wrong
I studied hard in order to my brother would pass too.
Correct
I studied hard so that my brother would pass too.
'In order to' cannot have a second subject. Use 'so that' when subjects differ.
Wrong
She exercises so that stay healthy.
Correct
She exercises so that she can stay healthy.
'So that' needs a subject + modal verb (can/will). Cannot be used like 'in order to'.
Wrong
We bought a tent in order to we could camp in the forest.
Correct
We bought a tent so that we could camp in the forest.
'In order to' takes only a base verb. For different subjects or emphasis, use 'so that'.
KEY TAKEAWAYS

What to Remember

  • Both 'so that' and 'in order to' express purpose, but they have different grammatical structures.
  • 'In order to' is followed by an infinitive verb in its base form without a subject.
  • 'So that' is followed by a complete clause containing both a subject and a conjugated verb.
  • Use 'in order to' when the subject of both clauses is the same person or thing.
  • Use 'so that' when you need to show the result or when the subjects are different.
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