Be Terrified To Do vs. Terrified Of Something distinguishes two directly documented complement patterns for the adjective “terrified.” Use terrified + to-infinitive for the directly documented infinitival construction; use terrified 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.
ReviewedEvidence1 sourceSectionEnglish Usage
Quick answer
Use terrified + to-infinitive when the adjective takes its documented infinitive complement; use terrified of + noun phrase when the complement is introduced by the documented preposition.
Key details
Confusion Familyadjective-complement
Rule Familyadjective complementation
Termsterrified + to-infinitive, terrified of + noun phrase
Choose the right form
Decision table for Be Terrified To Do vs. Terrified Of Something
Meaning / situation
Construction
Decision
intense fear attached to taking an action
terrified + to-infinitive
use the infinitive for the feared action
intense fear directed toward a thing, event, or situation
terrified of + noun phrase
use “of” for the object of fear
Quick tests
Action-or-object test
Are you afraid to take the action, or afraid of the thing/situation itself?
If yes: Use “terrified to + verb.”
If no: Use “terrified of + noun phrase.”
Caveat: The guide compares the two attested complement shapes and does not attempt to catalog every possible use of “terrified.”
Examples
Example
She was terrified to open the message.
The infinitive names the action she feared taking.
Example
She was terrified of the consequences.
“Of” names the object of fear.
Example
He was terrified to climb because he was terrified of heights.
The example separates feared action from feared thing.
Further guidance
Core difference
Use terrified + to-infinitive for the directly documented infinitival construction; use terrified of + 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.
