The girl I love hates me
Is the sentence grammatically correct?
My teacher says it should be
the girl who I love hates me
The girl I love hates me
Is the sentence grammatically correct?
My teacher says it should be
the girl who I love hates me
Unfortunately, your teacher is wrong.
A relative pronoun can be dropped when the relative clause has a non-subject gap, that is, a missing element that is not functioning as the subject of the clause. In this case, the missing element is the direct object of the verb "love". Therefore, the relative pronoun can be safely omitted.
The girl [(who) I love ___ ] hates me
(The '___' indicates the gap)
Now compare:
*She is the girl [___ hates me]
The sentence above is ungrammatical. That's because the gap is in the subject position. It should be:
She is the girl who [___ hates me]
I hope your teacher didn't say that! The first is perfectly proper but for the second to be grammatical it would have to be "The girl whom I love"!
In the US such an instance of "who"/"whom" would be considered redundant or stuffy, and the usual usage would be:
The noun that I verb opposite-verb(s) me.
Or, the implied version:
The noun I verb opposite-verb(s) me.
Note: "noun who" vs. "noun that", the rule seems to be that for a proper noun, (one that refers to a specific individual, or emphasizes a person's unique traits), use who; and for a noun that emphasizes class or set membership, (i.e. the class or set of all beloved young women), use that.
So if there were three girls named Mary standing in a row, then to say:
The Mary who I love is that girl on the right.
...would distinguish the individual Mary #3 as your favorite, who happens to be girl #3 as well.