Complain About Doing vs. Complain To Do
Cambridge distinguishes complain about a subject from complain to a person, and standard preposition-complement grammar uses an -ing form when an action follows about. Do not confuse complain to + person with a to-infinitive. Complain can also introduce a that-clause, and a purpose infinitive may occur elsewhere in a larger sentence.
Use “complain about doing” when the action is the thing being complained about. “Complain to do” is not the parallel direct-complement construction.
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| the action is the subject of the complaint | complain about + -ing | Use the -ing form after “about.” |
| a person or body receives the complaint | complain to + person/body | Use “to” before the recipient, not as an infinitive marker. |
| the complaint is expressed as a proposition | complain that + clause | Use a that-clause when that structure fits the meaning. |
Quick tests
Meaning / construction test
Is the following action itself what someone is complaining about?
If yes: Use “complain about” + -ing for that action.
If no: If you are naming the recipient, use “complain to” + person/body; if you are stating the complaint, a that-clause may fit.
Caveat: A to-infinitive can appear elsewhere for another function, such as purpose; this guide addresses the direct complement that names the complaint.
Examples
She complained about waiting so long.
The waiting is the subject of the complaint.
Customers complained to the manager about the delay.
“To” introduces the recipient; “about” introduces the topic.
He complained that the room was too cold.
A that-clause states the content of the complaint.
Further guidance
Boundary
Do not confuse complain to + person with a to-infinitive. Complain can also introduce a that-clause, and a purpose infinitive may occur elsewhere in a larger sentence.
Construction
Cambridge distinguishes complain about a subject from complain to a person, and standard preposition-complement grammar uses an -ing form when an action follows about.
Decision
Use “complain about doing” when the action is the thing being complained about. “Complain to do” is not the parallel direct-complement construction.
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.
- complain — Cambridge Dictionary (opens in a new tab)Cambridge Dictionary · Dictionary evidence distinguishing complain about a subject, complain to a person, and complain that clauses
- Verb patterns: verb + infinitive or verb + -ing? (opens in a new tab)Cambridge Dictionary · Verb-complement patterns, including verbs taking -ing, to-infinitive, or both with meaning differences