Overview
'Because' introduces a reason and is a subordinating conjunction (I stayed home because it was raining). 'So' introduces a result and is a coordinating conjunction (It was raining, so I stayed home). They express cause-effect relationships from opposite directions.
Because vs. So
- becauseBecause = reason → She left early because she was tired.
- soSo = result → She was tired, so she left early.
- positionBecause can start the sentence: Because it rained, we stayed home.
- positionSo always links two clauses: clause, so clause.
Clause structure
- Reason → Result: It rained (reason), so we cancelled (result).
- Result ← Reason: We cancelled because it rained.
- Use a comma before so: She was cold, so she wore a coat.
Common Mistakes
- ❌ Because it was raining, so we stayed. → ✅ Use one connector only.
- ❌ He was tired but he took a nap. → ✅ He was tired, so he took a nap.
- ❌ She failed because she revised a lot. → ✅ Check logic — reason must match.
When to use
Explaining reasons
I stayed because I was interested.
Showing results
The price rose, so demand fell.
Essay writing
Because of the pandemic, plans changed.
Conversations
I was hungry, so I ordered pizza.