Hypothesis vs Theory

When to use each in English, with meaning, register, and examples.

 HypothesisTheory
MeaningAn idea or guess that can be tested.An idea or explanation that tries to explain something.
Registerformal-
CEFR levelB2B1
Part of speechnounnoun
Usage notesUsed mainly in academic and scientific contexts. Avoid using it in everyday conversation as it's too technical for casual discussions.Used in academic and everyday contexts. Avoid in casual conversations unless discussing ideas or concepts.

Frequently asked questions: Hypothesis vs Theory

What's the difference between "Hypothesis" and "Theory"?

"Hypothesis" means: An idea or guess that can be tested. "Theory" means: An idea or explanation that tries to explain something.

When should I use "Hypothesis" and "Theory"?

"Hypothesis" is formal.

Are "Hypothesis" and "Theory" the same CEFR level?

"Hypothesis" is at B2, "Theory" is at B1 on the CEFR scale.