Please explain the error in the following:
He looks more depressed than her but I don't know the reason.
Is there any error in it? My book says her should be replaced by she. This confuses me often, please explain.
Please explain the error in the following:
He looks more depressed than her but I don't know the reason.
Is there any error in it? My book says her should be replaced by she. This confuses me often, please explain.
Native speakers often say
He looks more depressed than her.
but the objective-case her is considered [has long been considered] to be sub-standard. The standard version is
He looks more depressed than she does.
where "she does" means "she looks depressed".
He looks more depressed than she [looks depressed].
What is being compared is "he looks depressed" versus "she looks depressed".
However, very few native speakers would say:
He looks more depressed than she.
The overwhelming majority would say:
He looks more depressed than she does.
He looks more depressed than her/she but I don't know the reason.
In constructions like this, both forms of the pronoun are possible depending on its function in the clause, i.e. whether it is an immediate complement of a preposition or the subject of a reduced clause.
If it is understood as the complement of the preposition than, it is accusative her.
If it is subject of a reduced clause, the choice of case depends on the style.
In formal style, it appears as nominative (He looks more depressed than she ___), where the missing verb can be inserted to give the unreduced clause He looks more depressed than she does/looks.
But informal style has the accusative her (He looks more depressed than her ___), where the missing verb cannot be inserted.
Some speakers find I obtrusively formal and me obtrusively informal, and hence avoid both constructions by retaining the verb:
He looks more depressed than she does/looks but I don't know the reason.
The word "than" is a subject of debate among scholars and dictionaries. Some consider it a preposition, others consider it a conjunction, and yet others say it's neither of the above. The case of the following pronoun varies accordingly.
There are many appearances of "than" in both ways (e.g. "than her" and "than she") in classic literature and other text that are considered proper English.
You may refer to the Wikipedia article or to this post or this post in ELU for a longer discussion of this topic. Searching for "than me or than I" on Google would also show a surprising number of discussions.
None of the two versions is strictly incorrect; "than her" is probably more common in spoken English, but there are good arguments for using "than she" instead.
Not that this seems to be a matter of opinion, and whichever one you use, there will be people who will claim that it is incorrect.