is to be followed by the objective or subjective case of a pronoun is much discussed in usage guides. When, as a conjunction, than
introduces a subordinate clause, the case of any pronouns following than
is determined by their function in that clause: He is younger than I am. I like her better than I like him.
is followed only by a pronoun or pronouns, with no verb expressed, the usual advice for determining the case is to form a clause mentally after than
to see whether the pronoun would be a subject or an object. Thus, the sentences He was more upset than I
and She gave him more sympathy than I
are to be understood, respectively, as He was more upset than I was
and She gave him more sympathy than I gave him.
In the second sentence, the use of the objective case after than
(She gave him more sympathy than me
) would produce a different meaning (She gave him more sympathy than she gave me
). This method of determining the case of pronouns after than
is generally employed in formal speech and writing. Than
occurs as a preposition in the old and well-established construction than whom
: a musician than whom none is more expressive.
In informal, especially uneducated, speech and writing, than
is usually treated as a preposition and followed by the objective case of the pronoun: He is younger than me. She plays better poker than him, but you play even better than her.
See also but1