Be Unhappy To Do vs. Unhappy About Something distinguishes two directly documented complement patterns for the adjective “unhappy.” Use unhappy + to-infinitive for the directly documented infinitival construction; use unhappy 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.
ReviewedEvidence1 sourceSectionEnglish Usage
Quick answer
Use unhappy + to-infinitive when the adjective takes its documented infinitive complement; use unhappy about + noun phrase when the complement is introduced by the documented preposition.
Key details
Confusion Familyadjective-complement
Rule Familyadjective complementation
Termsunhappy + to-infinitive, unhappy about + noun phrase
Choose the right form
Decision table for Be Unhappy To Do vs. Unhappy About Something
Meaning / situation
Construction
Decision
reaction to an event expressed as an action
unhappy + to-infinitive
use the infinitive construction
dissatisfaction or sadness about a named matter
unhappy about + noun phrase
use “about” to introduce the matter
Quick tests
Event-or-matter test
Are you presenting the upsetting event through a verb, or naming the matter itself?
If yes: Use “unhappy to + verb.”
If no: Use “unhappy about + noun phrase.”
Caveat: The reviewed evidence supports these complement patterns; it does not make every other possible use of “unhappy” part of this comparison.
Examples
Example
We were unhappy to learn that the venue had closed.
The infinitive presents the event that caused the reaction.
Example
They were unhappy about the last-minute cancellation.
“About” introduces the matter causing the dissatisfaction.
Example
She was unhappy to leave and unhappy about the timing.
The sentence contrasts an event expressed by an infinitive with a named matter.
Further guidance
Core difference
Use unhappy + to-infinitive for the directly documented infinitival construction; use unhappy 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.
Be Afraid To Do vs. Afraid Of Something distinguishes two directly documented complement patterns for the adjective “afraid.” Use afraid + to-infinitive for the directly documented infinitival construction; use afraid of + noun phrase for the separately documented prepositional construction. The page stays within those attested patterns and does not infer a broader rule from synonymy.
Be Alarmed To Do vs. Alarmed At Something distinguishes two directly documented complement patterns for the adjective “alarmed.” Use alarmed + to-infinitive for the directly documented infinitival construction; use alarmed at + noun phrase for the separately documented prepositional construction. The page stays within those attested patterns and does not infer a broader rule from synonymy.
Be Amused To Do vs. Amused By Something distinguishes two directly documented complement patterns for the adjective “amused.” Use amused + to-infinitive for the directly documented infinitival construction; use amused by + noun phrase for the separately documented prepositional construction. The guide stays within those attested patterns and does not infer a broader rule from synonymy.
Be Annoyed To Do vs. Annoyed About Something distinguishes two directly documented complement patterns for the adjective “annoyed.” Use annoyed + to-infinitive for the directly documented infinitival construction; use annoyed 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.
Be Astonished To Do vs. Astonished At Something distinguishes two directly documented complement patterns for the adjective “astonished.” Use astonished + to-infinitive for the directly documented infinitival construction; use astonished at + noun phrase for the separately documented prepositional construction. The page stays within those attested patterns and does not infer a broader rule from synonymy.
Be Astounded To Do vs. Astounded By Something distinguishes two directly documented complement patterns for the adjective “astounded.” Use astounded + to-infinitive for the directly documented infinitival construction; use astounded at/by + noun phrase for the separately documented prepositional construction. The guide stays within those attested patterns and does not infer a broader rule from synonymy.
