Be Fortunate To Do vs. Fortunate In Something distinguishes two attested complement patterns for the same adjective. Use fortunate + to-infinitive for the adjective followed by its documented complement pattern; use fortunate in + noun phrase for the separately documented construction. The constructions are not interchangeable simply because they share the adjective; choose the pattern that matches the grammatical relationship you mean.
ReviewedEvidence1 sourceSectionEnglish Usage
Quick answer
Use fortunate + to-infinitive when the adjective introduces that documented complement; use fortunate in + noun phrase when you mean the second documented relationship.
Key details
Confusion Familyadjective-complement
Rule Familyadjective complementation
Termsfortunate + to-infinitive, fortunate in + noun phrase
Further guidance
Core difference
Use fortunate + to-infinitive for the adjective followed by its documented complement pattern; use fortunate in + noun phrase for the separately documented construction.
Style Boundary
Treat the distinction as a complement-pattern choice, not as a claim that every nearby preposition or clause is impossible. Follow the directly documented construction for the intended 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.
