In the last few years, I’ve increasingly heard people including the preposition ‘of’ after an adjective in creating phrases such as not that big of a deal and how big of a problem.
To my ear, ‘of’ after adjectives in such phrases is unnecessary and sounds completely wrong.
I’ve heard this construction mainly from Americans, particularly younger ones. It seems to be mainly informal spoken usage, though I’ve occasionally seen it in writing.
A quick look at Google NGram seems to support my impression that this construction is fairly young. I plotted 3 phrases:
- ‘how big of a’. This was almost non-existent until the mid-1990s, and then took off rapidly.
- ‘how big of’. This tracks very closely ‘how big of a’. It seems that almost all instances of ‘how big of’ are also instances of ‘how big of a’.
- ‘how big a’. This has increased slowly since the mid-1990s, but looks as though it will soon fall behind ‘how big of (a)’.
I also looked at figures for ‘how big’, which is too frequent to be displayed usefully on the same graph. It is still much more common than ‘how big a’ or ‘how big (of) a’, and its frequency has trebled since the mid-1990s.
‘Intrusive of’
Google’s AI tells me that the legal lexicographer Bryan Garner coined the phrase ‘intrusive of’ in his book Garner’s Modern American Usage. It refers to the preposition ‘of’ when spoken idioms insert it unnecessarily and incorrectly between an adjective and a noun.
Links
I found some discussion on:
- English Language & Usage at Stack Exchange https://english.stackexchange.com/questions/30011/how-big-of-a-problem-vs-how-big-a-problem
- Quora https://www.quora.com/Is-I-realized-how-good-of-a-person-he-is-grammatically-correct
- Quick and Dirty Tips https://www.quickanddirtytips.com/qdtarchive/the-intrusive-of/
Big of you
I can think at least one context where ‘of’ is needed: in phrases such as ‘big of you’. In that phrase, ‘of you’ seems to be a concise way of saying ‘on your part’.
Conclusion
The ‘intrusive of’ in phrases such as how big of a problem seems to be getting more and more common in informal speech, especially by younger Americans. I doubt whether I will ever use it myself, and I would certainly not suggest using it in formal writing.