It was very unfortunate of him to have lost the battle.
In this sentence, is the usage of the preposition "of" correct?
A more natural preposition to use in this context would be "for".
"It was very unfortunate for him to have lost the battle."
Using "of" would seem more natural in a sentence such as, "it was very rude of him to have said that". The difference seems to be that being rude is something one does more actively, whereas being unfortunate is something that happens to one. Compare, "that was very kind of him," and "that was lucky for him."
One way to sidestep the problem entirely would be to use a relative clause, with an optional phrase indicating whose misfortune we are concerned with:
"It was very unfortunate (for whomever) that he lost the battle."
Of and for are used in two different constructions.
The (very) Adjective
of Noun Phrase
construction, like very rude/kind of you,
attributes Adjective
to Noun Phrase
, which implies in this case that you are rude/kind.
(at least in the view of the speaker).
The for Noun Phrase
to Verb Phrase
, or Complete Infinitive, construction.
Since infinitives are verbs, they have to have subjects, even if the subjects don't appear
in the infinitive clause. But sometimes their subjects do appear, and occasionally the
subject noun phrase is marked with for, just as the infinitive verb phrase is marked with to.
Very unfortunate of/for him to have lost the battle can be broken up two ways:
(It was) [Very unfortunate of him] [to have lost the battle]
This can be transformed into
[To have lost the battle] was [very unfortunate of him]
This attributes the predicate adjective unfortunate to the pronoun him.
(It was) [Very unfortunate] [for him to have lost the battle]
This can be transformed into
[For him to have lost the battle] was [very unfortunate]
This attributes unfortunate to the infinitive clause for him to have lost the battle.