So – The Coordinating Conjunction
Most students know how to use ‘so’. It is a coordinating conjunction, which means it can join two independent clauses. It is used to show cause & effect (result). For example:
I was hungry, so I ate.
The printer was broken, so we couldn’t use it.
[cause], so [effect]
So has a meaning of ‘therefore’ here (except ‘therefore’ is not a conjunction).
So (that) – The Subordinating Conjunction
So that has a meaning similar to ‘in order to/in order that’. It describes the purpose of an action. It begins a subordinate clause (a clause that is dependent on a main clause). For example:
The teacher spoke slowly so that his students would understand the lesson.
Here, his students understanding the lesson is the purpose/aim of the action of speaking slowly. It is not the result. In this sentence, we don’t know the result. We only know that he spoke slowly for the purpose of helping them understand.
She exercises so that she can lose weight. (this is her purpose for exercising)
We should recycle so that our children can enjoy our planet in the future. (purpose, not effect)
The Confusing Part: ‘That’ is optional in ‘So that’
You can say either of these:
She exercises so that she can lose weight. (purpose)
She exercises so she can lose weight. (purpose)
The word (that) is optional.
|To talk about purpose||so||so that|
|To talk about a result (effect)||so|
In other words, anytime you can say ‘so that’, you can also shorten it to ‘so’. However, you cannot use ‘so that’ if you are talking about the effect (result) of an action (you can only use so). For example:
It was cheap so
that I bought it. (we are talking about the result, not purpose)
What’s the answer here?
1. The movie was boring, _______ we stopped watching it. (show answer)
Answer = so. We aren’t talking about purpose here. We are talking about the result.
2. She is studying Spanish ______ she can communicate when she moves to Spain next year. (show answer)
Answer = so (that). We are talking about purpose here, not result. We don’t know the result because it will happen in the future.
Try some more exercises on the difference between so and so that below.
Practice Exercises: So vs. So that
In these exercises, choose between ‘so’ as a coordinating conjunction used for cause and effect, and ‘so (that)’ as a subordinate conjunction used to show purpose.
- The piano was heavy we needed two people to move it.
- No one invited him to the party he didn’t come.
- We’re painting our house it will look better.
- the children would listen, the teacher raised her voice.
- I am a man I am not a woman.
- We hired a cleaner our house is clean now.
- We hired a cleaner our house would be clean for the party.
If you have any questions, please leave a comment below.
— Matthew Barton / Creator of Englishcurrent.com (ESL)