B1noun 1K

Theory

UK //ˈθɪəri// US //ˈθɪəri// Pronunciation

Definition

A set of principles or ideas intended to explain something.

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In simple words: An idea or explanation that tries to explain something.

Examples

• Einstein's theory of relativity revolutionized our understanding of space and time.
• The theory of evolution explains the diversity of life on Earth.
• Many scientists support the theory that climate change is caused by human activities.
• She developed a theory about how people learn languages.
• In his speech, he referenced a fascinating theory regarding the origins of the universe.

Usage notes

Used in academic and everyday contexts. Avoid in casual conversations unless discussing ideas or concepts.

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Grammar pattern

standalone noun

Memory hint

Think of 'theory' as a 'thought' - both start with 'th'.

Collocations

• scientific theory
• theory of relativity
• theory in practice
• theory and practice

Synonyms

• hypothesis
• principle
• model
• framework
• concept

Antonyms

• fact
• truth

Common mistakes

• Confused with 'hypothesis'; a theory is more established.
• Incorrectly used to mean 'theory' as just a guess or opinion.