English UsageComparison guide
Shutdown vs. Shut Down
“Shutdown” is a one-word noun for an occasion when a business, system, or machine stops operating. “Shut down” is the two-word phrasal verb for causing or undergoing that stop.
Use “shutdown” for the noun and “shut down” for the verb.
Key details
Confusion Familyword-boundary
Noun Variant Scopeshutdown is the noun; shut down is the phrasal verb
Rule Familyorthographic-boundary
Termsshutdown, shut down
Choose the right form
| If you mean / need | Use | Why |
|---|---|---|
| an event or period when operation stops | shutdown | It is the noun. |
| to stop operating or cause something to stop | shut down | It is the phrasal verb. |
Further guidance
Core difference
A system can “shut down,” while the event itself is a “shutdown.”
Fast Test
If tense works—“shut down yesterday,” “shutting down now”—you are using the two-word verb.
Variant Boundary
The core distinction here is grammatical role: noun versus phrasal verb.
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.
- SHUTDOWN — English meaning (opens in a new tab)Cambridge Dictionary · One-word noun “shutdown”
- SHUT (SOMETHING) DOWN — English meaning (opens in a new tab)Cambridge Dictionary · Two-word phrasal verb “shut down”