Be Dismayed To Do vs. Dismayed By Something distinguishes two directly documented complement patterns for the adjective “dismayed.” Use dismayed + to-infinitive for the directly documented infinitival construction; use dismayed by + 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 dismayed + to-infinitive when the adjective takes its documented infinitive complement; use dismayed by + noun phrase when the complement is introduced by the documented preposition.
Key details
Confusion Familyadjective-complement
Rule Familyadjective complementation
Termsdismayed + to-infinitive, dismayed by + noun phrase
Choose the right form
Decision table for Be Dismayed To Do vs. Dismayed By Something
Meaning / situation
Construction
Decision
reaction followed by a reported/discovered event
dismayed + to-infinitive
present the event with the infinitive
cause of dismay
dismayed by + noun phrase
name the cause with “by”
Quick tests
Event-or-source test
Are you describing what someone was dismayed to learn/find/see, or naming the thing that caused the dismay?
If yes: Use “dismayed to + verb” for the event presentation.
If no: Use “dismayed by + noun phrase” for the source/cause.
Caveat: Stay within the attested complement patterns rather than generalizing from near-synonyms.
Examples
Example
We were dismayed to learn that the venue had closed.
The infinitive introduces the event learned.
Example
They were dismayed by the sudden change.
“By” introduces the cause of the reaction.
Example
She was dismayed to find the file missing.
The infinitive can present a discovered state or event.
Further guidance
Core difference
Use dismayed + to-infinitive for the directly documented infinitival construction; use dismayed by + 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.
