Worry About Doing vs. Worry To Do
Cambridge grammar identifies about as the most usual preposition after worry, and an action used as a prepositional complement takes an -ing form. Worry also occurs with noun phrases and that-clauses. This guide does not treat every later to-infinitive in a sentence as a complement of worry.
Use “worry about doing” when the action is the subject of concern. “Worry to do” is not the usual parallel direct-complement construction.
Key details
Choose the right form
| Context | Use | Decision |
|---|---|---|
| action is the subject of concern | worry about + -ing | “About” is the usual preposition after “worry,” and an action after a preposition takes an -ing form. |
| concern is expressed with a thing/person | worry about + noun phrase | A noun phrase can follow “about.” |
| concern is expressed as a proposition | worry + that-clause | A that-clause is a separate documented pattern. |
| a later “to do” belongs inside another phrase | analyze its local role | Do not assume every later to-infinitive is a direct complement of “worry.” |
Quick tests
Decision test
Is the action itself the thing you are worrying about?
If yes: Use “worry about + -ing.”
If no: Use the construction required by the actual complement; “worry to do” is not the usual parallel direct-complement pattern.
Caveat: This is a complement-pattern distinction, not a ban on every to-infinitive that may appear later in a sentence containing “worry.”
Examples
I worry about missing the train.
The action causing concern follows “about” in -ing form.
She worries about the cost.
A noun phrase follows the usual preposition “about.”
I worry that we may be late.
A that-clause is a separate way to express the content of the worry.
I worry about what to do next.
The infinitive belongs inside “what to do,” not as a direct “worry to do” complement.
Further guidance
Boundary
Worry also occurs with noun phrases and that-clauses. This guide does not treat every later to-infinitive in a sentence as a complement of worry.
Construction
Cambridge grammar identifies about as the most usual preposition after worry, and an action used as a prepositional complement takes an -ing form.
Decision
Use “worry about doing” when the action is the subject of concern. “Worry to do” is not the usual 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.
- Prepositions: worry (opens in a new tab)Cambridge Dictionary · Grammar guidance identifying about as the most usual preposition after worry
- 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