Q. When I encounter a restrictive clause with multiple elements, do I put a comma at the end of the last element? For example: The woman who was blonde, green-eyed, and slim said hello to me. Or is it: The woman who was blonde, green-eyed, and slim, said hello to me.
A. Commas are like parentheses when they indicate nonrestriction, so you need two of them, but in a restrictive clause you don’t need them at all: The woman who was blonde, green-eyed, and slim said hello. In a nonrestrictive clause, you need a pair, whether it’s parentheses or commas: The woman (who was blonde, green-eyed, and slim) said hello. Or, The woman, who was blonde, green-eyed, and slim, said hello.