Tom is the only student (who/ that) passed the exam.
The following is quoted from Practical English Usage, Second Edition, page 490.
That is especially common after quantifiers like all, every(thing), some(thing), any(thing), no(thing), none, little, few, much, only, and after superlatives.
Does this mean that using "who" is grammatically wrong? I would appreciate it if you answered my question.
Omar Ahmed Does this mean that using "who" is grammatically wrong? No. Who is also correct and common.
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Omar AhmedDoes this mean that using "who" is grammatically wrong?
No. Who is also correct and common.
Omar AhmedTom is the only student (who/ that) passed the exam.
I always use "who" with people.
"That" is used with things.
Advanced physics is the only test that Tom failed.
Tom is the only student (who/ that) passed the exam.
It's a free choice with personal antecedents, though some prefer "who" when the relative word is subject, as it is here.
Conversely, there is a preference for "that" when it is object, as in
The boy that they had found hiding in the cupboard.
But they are only preferences - there is nothing grammatically