Having such a famous man for a father must have had an effect on Jason's childhood.
In this sentence I can't understand how for is used. I haven't read such a sentence before so I find it difficult to understand. I think 'as' in place of 'for' makes more sense.
Anyone please explain where I'm wrong because it's given on a English grammar check website.
Either of these two definitions of for at oxforddictionaries.com might help...
4 Having (the thing mentioned) as a purpose or function.
‘networks for the exchange of information’
‘the necessary tools for making a picture frame’
...where the relevant role/function of the aforementioned famous man is to be a father. Alternatively, it may make more sense to some see it in terms of...
7 Representing (the thing mentioned)
‘the ‘F’ is for Fascinating’
...where we (the celebrity-obsessed public) see a very famous man (that we don't even know personally, but what the addressee sees is his father (the real man, not the public facade).
Note that it wouldn't make any difference if the sentence were changed to...
Having such a famous man as a father must have had an effect on Jason's childhood.
But note also that whereas it's perfectly idiomatic to say...
As a father, I don't think 15-year-olds should be drinking in bars
...it's most definitely not idiomatic to replace as with for in that context.
