For the sense “volunteer to perform an action,” Oxford documents offer + to-infinitive. The verb also accepts ordinary objects, so an -ing form can be noun-like in some contexts without creating a balanced gerund-versus-infinitive choice.
ReviewedEvidence2 sourcesSectionEnglish Usage
Quick answer
Use “offer to do” when volunteering to perform an action. “Offer” can also take noun-like objects, but bare “offer doing” is not the ordinary equivalent of the volunteering pattern.
Key details
Confusion Familygrammar-and-usage distinction
Rule Familyverb complement pattern
TermsOffer Doing, Offer To Do
Further guidance
Decision
If the subject is volunteering to perform the following action, choose offer + to-infinitive.
Object Boundary
Offer also takes noun/object complements; keep those transitive uses separate from the “offer to do” volunteering construction.
To Infinitive
Use offer + to-infinitive to say that someone is willing to perform an action.
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.
Cambridge documents both admit + -ing and admit to + -ing for acknowledging something. Other passive patterns such as “be admitted to be” are separate constructions.
Both patterns are standard. “Advise waiting” recommends an action generally or in context, while “advise him to wait” names the person who is advised to perform it. A that-clause is another standard option.
When “afford” is followed directly by another verb, standard learner references use a to-infinitive: “afford to do.” An -ing form can appear elsewhere in a sentence, but it is not a like-for-like direct complement after “afford.”
“Agree to do” expresses consent to take an action. An -ing form normally follows a preposition in patterns such as “agree with doing,” which expresses approval rather than the direct promise-to-act construction.
Cambridge documents aim + to-infinitive for intention and aim at for directing effort toward an objective. Do not omit the preposition and present bare “aim doing” as equivalent to “aim to do.”
“Allow” can take an activity as its object, as in “allow smoking,” or a person/thing followed by a to-infinitive, as in “allow visitors to enter.” The patterns answer different structural questions: what is allowed versus who is allowed to do what.
