Cambridge marks tend + to-infinitive for things that usually happen or people who are likely to behave in a particular way. Keep the separate transitive sense of tend, meaning to care for or attend to something, distinct from the tendency construction.
ReviewedEvidence2 sourcesSectionEnglish Usage
Quick answer
Use “tend to do” for a usual tendency or likelihood; bare “tend doing” is not the equivalent complement in that sense. Keep the separate transitive sense of tend, meaning to care for or attend to something, distinct from the tendency construction.
Key details
Confusion Familygrammar-and-usage distinction
Rule Familyverb complement pattern
TermsTend Doing, Tend To Do
Further guidance
Boundary
Keep the separate transitive sense of tend, meaning to care for or attend to something, distinct from the tendency construction.
Construction
Cambridge marks tend + to-infinitive for things that usually happen or people who are likely to behave in a particular way.
Decision
Use “tend to do” for a usual tendency or likelihood; bare “tend doing” is not the equivalent complement in that sense.
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.