Be Concerned To Do vs. Concerned About Something
Be Concerned To Do vs. Concerned About Something distinguishes two directly documented complement patterns for the adjective “concerned.” Use concerned + to-infinitive for the directly documented infinitival construction; use concerned about + noun phrase for the separately documented prepositional construction. The page stays within those attested patterns and does not infer a broader rule from synonymy.
Use concerned + to-infinitive when the adjective takes its documented infinitive complement; use concerned about + noun phrase when the complement is introduced by the documented preposition.
Key details
Choose the right form
| Meaning / situation | Construction | Decision |
|---|---|---|
| documented infinitive complement | concerned to + verb | use where the intended formal construction calls for the infinitive |
| worry/interest focused on a matter | concerned about + noun/-ing | name the matter that causes concern |
Quick tests
Complement-purpose test
Is the sentence using the documented infinitive construction, or naming the matter about which concern exists?
If yes: Use “concerned to + verb” only when that infinitive construction expresses the intended relation.
If no: Use “concerned about + noun/-ing” when naming the subject of concern.
Caveat: Do not assume the two complements are freely interchangeable; the intended sense and register matter.
Examples
The editors were concerned to make the distinction clear.
This uses the documented infinitive complement in a formal sentence.
The editors were concerned about the delay.
“About” names the subject causing concern.
If the intended meaning is worry about an issue, the “about” pattern is usually the direct way to name that issue.
This keeps the complement choice tied to meaning.
Further guidance
Core difference
Use concerned + to-infinitive for the directly documented infinitival construction; use concerned about + noun phrase for the separately documented prepositional construction.
Style Boundary
Treat this as a comparison of directly documented complement patterns, not as a claim that every other complement is impossible. Choose the construction that matches the intended grammatical relationship.
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.
- CONCERNED — Cambridge Dictionary (opens in a new tab)Cambridge University Press & Assessment · Direct dictionary evidence for concerned + to-infinitive and concerned about + complement