Academic / B1

THEERR-ee/ˈθɪəri/

A theory is an idea that explains how or why something happens. In theory the plan should work — but perhaps not in practice; that contrast is a favourite in exams. A hypothesis is a starting idea in science; an opinion is more personal. Theoretical / theoretically are the family words; do not use theory for a simple guess unless you mean a structured explanation.

Meaning

An idea that explains how or why something happens.

Examples

• “In theory the plan should work.”
• “In theory we have enough chairs for everyone.”
• “Her theory about the delay turned out to be right.”

Good to know

in theory vs in practice. a theory about / of. Science start: hypothesis. Adjective: theoretical.

Near in meaning

hypothesis

Topics

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