Breakdown vs. Break Down
“Breakdown” is a noun, while “break down” is a phrasal verb. The pair appears across several senses—including failure, division, analysis, and mechanical problems—but the word boundary tracks the grammatical role.
Use “breakdown” as a noun (“a breakdown of costs”). Use “break down” as a verb (“break down the costs” or “the car broke down”).
Key details
Choose the right form
| Meaning / situation | Construction | Decision |
|---|---|---|
| noun: failure, analysis, or division into parts | breakdown | use the closed noun |
| verb: fail or divide/analyze | break down | use the two-word verb |
Quick tests
Part-of-speech test
Can the expression take tense or an object as a verb?
If yes: Use “break down.”
If no: If it names the event or analysis, use “breakdown.”
Caveat: Meaning varies by context, but the spelling distinction tracks noun versus verb.
Examples
The report includes a breakdown of costs.
“Breakdown” is a noun.
Please break down the costs by region.
“Break down” is a verb.
The van broke down on the motorway.
The phrasal verb can inflect for tense.
Further guidance
Core difference
Use “breakdown” when naming the event, failure, or analysis. Use “break down” when describing the action or process.
Fast Test
If you can place “to” before it—“to break down the costs”—use two words. If you can put an article before it—“a breakdown of costs”—use one word.
Sense Boundary
Both forms have several related senses, so the one-word/two-word choice depends on grammatical role rather than on one single definition.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Breakdown — English meaning (opens in a new tab)Cambridge University Press · Dictionary noun record for breakdown
- Break down — English meaning (opens in a new tab)Cambridge University Press · Dictionary phrasal-verb record for break down