Witness can occur with an object followed by a bare infinitive or an -ing form in event-perception contexts. Use the contrast to express whole-event versus ongoing-event viewpoint rather than treating the forms as interchangeable in every sentence.
ReviewedEvidence2 sourcesSectionEnglish Usage
Quick answer
Both constructions can occur: “witness someone do” presents the witnessed event as a whole, while “witness someone doing” foregrounds the person engaged in the activity.
Key details
Confusion Familygrammar-and-usage distinction
Rule Familyverb-complement and object pattern
TermsWitness Someone Do, Witness Someone Doing
Further guidance
Boundary
Witness also works as a transitive verb with a noun object (“witness an accident”); the do/doing contrast applies only when a following verb phrase is licensed.
Construction
Oxford’s perception-pattern guidance includes witness + object + bare infinitive, while Cambridge documents witness + object + -ing usage.
Decision
Use do for the witnessed event viewed as a complete occurrence; use doing when the activity in progress is the focus.
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.
Oxford directly documents “argue somebody into doing something” for persuading somebody by giving reasons. The cited construction evidence directly supports into + -ing; it does not license “argue someone to do” as an equivalent complement pattern.
When ask means request an action from a person, Cambridge documents ask + person + to-infinitive. Bare “ask doing” is not the ordinary request complement for that meaning.
Cambridge directly documents both badger + object + into + -ing and badger + object + to-infinitive for repeated pressure or requests that push someone toward an action. The verb also covers repeated questioning, so context must show whether the sentence is about persistent persuasion or interrogation rather than assuming every use names a requested action.
Cambridge directly illustrates bamboozle + object + into + -ing for deceiving someone so that the person takes an action. The cited entry does not establish bamboozle + object + to-infinitive as an equally documented alternative, so this guide does not manufacture a two-way rule.
Cambridge explicitly documents beg + object + to-infinitive for an urgent request and also records beg for + noun and other request patterns. A following -ing form may appear elsewhere in a sentence, but it is not the ordinary replacement for the documented object + to-infinitive request construction.
Cambridge gives direct evidence for beguile someone into doing something in the literary persuade/attract/deceive sense. The cited entry supports the into + -ing construction; it does not establish beguile + object + to-infinitive as an equivalent pattern for this meaning.
