theory

word

/ˈθiɝi/
THEE-ree
/θˈiəɹi/
THEE-uh-ree

Definition

A theory is a set of ideas that explains why or how something happens. It can also mean an idea that is not yet proven, or the general principles of a subject rather than its practical use.

Usage & Nuances

Very common in science, education, and everyday speech. In daily conversation, 'theory' often means a guess or explanation ('My theory is...'), but in academic contexts it usually means a well-developed explanatory framework. Common combinations: 'scientific theory', 'in theory', 'theory and practice'. Don't confuse it with 'hypothesis', which is usually narrower and more testable.

Example Sentences

His theory about the moon was interesting.

basic

We studied music theory in class today.

basic

That theory is not proven yet.

basic

I have a theory about why the wifi keeps dropping.

natural

In theory, the plan should work, but I'm not fully convinced.

natural

That's just a theory—do you have any real evidence?

natural