Stop Someone From Doing vs. Stop Someone To Do
For the prevention meaning, standard English uses stop + person + (from) + -ing. A following to-infinitive can instead express purpose after stopping someone, so “stop someone to do” is not the corresponding prevention complement.
Use “stop someone from doing something” (or, in some contexts, “stop someone doing something”) when you mean prevent the action. Do not substitute “stop someone to do something” for that pattern.
Key details
Choose the right form
| Meaning / structure | Pattern | Decision |
|---|---|---|
| prevent a person from an action | stop + object + (from) + -ing | Use the documented prevention construction. |
| cause a person to stop, with a following purpose | stop + object + to-infinitive | The to-infinitive can explain why the person was stopped. |
| treat object + to-infinitive as the prevention complement | stop someone to do | Do not use this as a substitute for the from/-ing pattern. |
Quick tests
Prevention-versus-purpose test
Does the sentence mean prevent the person from carrying out the following action?
If yes: Use “stop + object + (from) + -ing.”
If no: If the person is stopped so that another action can be performed, a following to-infinitive can express purpose.
Caveat: A sentence such as “I stopped him to ask a question” does not mean “I prevented him from asking”; the to-infinitive has a different structural role.
Examples
The barrier stopped visitors from entering.
The from/-ing pattern expresses prevention.
Nothing stopped her completing the form.
The documented prevention pattern can occur without “from” in some contexts.
I stopped him to ask a question.
Here the to-infinitive gives the purpose of stopping him; it is not the prevention complement.
Further guidance
Boundary
A sentence such as “I stopped him to ask a question” can use the to-infinitive as a purpose adjunct—why I stopped him—not as the complement meaning “prevent him from asking.”
Construction
Oxford documents stop + object + (from) + -ing for preventing an action. Stop + to-infinitive is a different construction meaning to stop in order to do something.
Decision
Choose the from/-ing pattern for prevention; treat a to-infinitive after stop as a separate purpose structure unless the sentence has another clear analysis.
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.
- stop — Oxford Advanced Learner’s Dictionary (opens in a new tab)Oxford Learner’s Dictionaries · Stop + object + (from) -ing for preventing a person or thing from an action