# know by heart

CEFR B1 · Verb

Source: https://englishreference.com/word/know-by-heart
Updated: 2026-08-02

## Definition

to remember something so well that you can say it perfectly without looking at any notes.

For teachers: to have memorised something perfectly; to possess a complete mental record of a text or sequence.

## Examples

- I know all the song lyrics by heart.
- She had performed the monologue so many times that she knew it by heart and no longer needed the script.
- In an era of digital convenience, the ability to know long passages of poetry by heart is becoming a rare but deeply respected intellectual discipline.

## Pitfalls

- Not "I know it from heart" but "I know it by heart" — The correct preposition for this idiom is 'by', not 'from'.

## Usage notes

- Typically functions as a transitive verb phrase where the object follows 'know'.
- Teaching tip: contrast with 'memorize' (the process) versus 'know by heart' (the state of having finished the process); the heart was historically believed to be the seat of memory.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.