John McIntyre previews the approach of National Grammar Day over at You Don't Say. He gives some sensible principles to keep in mind, including this one that I particularly liked:
- "Individual stylistic preferences are that and no more. You may agree with H.W. Fowler that it is sensible to use that, generally, to introduce a restrictive clause and which, generally, to introduce a nonrestrictive clause, but it is not a rule, or even an unquestioned convention. It is an individual stylistic preference, like a taste for inserting commas to replicate the pauses of spoken language. You may want to restrict who to refer to people, that to animals and inanimate objects; but that is merely your preference, not a practice that you can oblige someone else to follow."