Confusing words explained
“assume” vs “suppose” — What’s the Difference?
Suppose implies thinking something is probably true; assume means treating it as fact for argument's sake.
Key takeaway
Quick Difference: assume vs suppose
Suppose implies thinking something is probably true; assume means treating it as fact for argument's sake.
assume vs suppose Side-by-Side Comparison
Meaning of assume
To suppose something is true without proof; to take on a responsibility.
To believe or accept something without checking if it is true, or to accept a responsibility.
Use 'assume' when you believe something without definite proof, or when officially taking on a duty.
- I assume you have your passport with you.
- The manager will assume control of the department next month.
Meaning of suppose
To believe or assume something is true without having proof; to think or imagine something in a hypothetical way.
To think or believe something is probably true, even without complete proof.
Use 'suppose' with that-clause or infinitive structure. 'Supposedly' means 'it is said that' or 'according to what people say'.
- I suppose you're right about that decision.
- Suppose we missed the train; what would we do next?
How to Remember the Difference
Assume = confidently take as true; suppose = consider hypothetically (softer, tentative).
Common Mistakes with assume and suppose
Mistake with assume
Wrong: I assume that he is coming tomorrow.
Correct: I assume he is coming tomorrow.
After 'assume', 'that' is optional in informal speech; 'I assume he is...' is more natural.
Mistake with assume
Wrong: Assuming your homework, it must be difficult.
Correct: Assuming your homework is difficult, we can help.
Use 'assuming' with a complete clause, not just a noun without context.
Mistake with suppose
Wrong: He is suppose to arrive tomorrow.
Correct: He is supposed to arrive tomorrow.
Use past participle 'supposed' after 'is', not 'suppose'.
Mistake with suppose
Wrong: What suppose you will do?
Correct: What do you suppose you will do?
Need auxiliary 'do' for question form: 'What do you suppose...?'
Practice Quiz: assume or suppose?
Choose the word that best completes each real example sentence.
Question 1
I _____ you have your passport with you.
Question 2
The manager will _____ control of the department next month.
Question 3
Never _____ people understand your accent without asking.
Pick at least one answer, then press Check answers to see how you did.
You scored 0 out of 3
Frequently Asked Questions About assume vs suppose
What’s the difference between “assume” and “suppose”?
Suppose implies thinking something is probably true; assume means treating it as fact for argument's sake.
When should I use “assume”?
Use 'assume' when you believe something without definite proof, or when officially taking on a duty.
When should I use “suppose”?
Use 'suppose' with that-clause or infinitive structure. 'Supposedly' means 'it is said that' or 'according to what people say'.
How can I remember assume vs suppose?
Assume = confidently take as true; suppose = consider hypothetically (softer, tentative).
Is it “assume” or “suppose” in example sentences?
Use the quiz above to test the pair with real example sentences from the available word data.