A recent column talks about "the improper use of a singular verb when a plural verb is required. For instance, the expression 'he is one of those people who ... ' is properly followed by a plural, not a singular verb."
My gut instinct was to agree with youbut then I thought about it. I'm inclined, in the specific construction "one of those people who" to say plural. The following verb clearly relates to people rather than "one of" or "he". Interesting example though.
"No man but a blockhead ever wrote except for money." Samuel Johnson.
I would use a singular verb. In fact, I just wrote something where that question came up. I did think about it, but I ended up using the singular verb. The example was something like, "I am one of those people who says...." Of course, I very well could be wrong.
Both agreements are common, so there's no question of either being 'improper'.
Structurally the relative clause 'who... ' is attached to 'those N', not to 'one', because the word 'those' gets its reference from 'those ... who ...'. It's not 'those (people over there)'. So the structure is 'He is [one of [those people who...]]' rather than 'He is one [of those people] [who ...]'. So we would expect the verb in the relative clause to agree with the plural 'those'.
But it doesn't always, and that's perfectly normal behaviour for English. We often get mismatches, compulsorily in 'a lot of N', optionally in other constructions such as 'a number of N'. The column that calls these normal English constructions 'improper' clearly doesn't know much about English grammar.
