It is easy when you say something becomes or unbecomes someone. In this case, no preposition is needed. It is another story when the verb turns into the adjective “(un)becoming”. I would like to understand which pick is correct:
a conduct (un)becoming a man
a conduct (un)becoming to a man
a conduct (un)becoming of a man
It is that inner feeling that tells me that the first sentence sounds awkward and misused. The variant with ‘to’ will be better in the verbal phrase “to conduct (un)becoming to a man”. Clearly, the choice becomes number three, or does it?
Best Answer
Evidently all three are grammatical:
(AHD)
(Longman Dictionary)
(http://www.oxforddictionaries.com/definition/english/unbecoming)