NO.
Who can refer to and thus modify ANY noun in a sentence (of course, within the constraints of the rules of noun modifiers), and Whom can also refer to and thus modify ANY noun in a sentence (within the constraints of the rules of noun modifiers).
The difference between Who and Whom lies
not in which nouns they can modify
but in what Who and Whom do within their own clauses
The difference is that
Who can be the subject or the object of its own clause
Whom can only be the object of its own clause
For example:
Ram, who is a cricketer, likes Shyam.
This sentence is correct
Ram is the subject
Who refers to the subject
Who acts as a subject in its clause “who is a cricketer”
Ram likes Shyam, who is a cricketer.
This sentence is correct
Shyam is the object
Who refers to the object
Who acts as a subject in its clause “who is a cricketer”
Ram likes Shyam, whom is a cricketer.
This sentence is Incorrect.
Shyam is the object
Whom refers to the object
Whom acts as a subject in its clause “whom is a cricketer”. This usage is NOT ALLOWED. Thus, the sentence is incorrect.
Ram likes Shyam, whom many admire.
This sentence is correct.
Shyam is the object.
Whom refers to the object.
Whom acts as an object in its clause “whom many admire” (Subject: many; Verb: admire; Object: Whom [Shyam])
Ram, whom many admire, likes Shyam
This sentence is correct.
Ram is the subject
Whom refers to the subject.
Whom acts as an object in its clause “whom many admire” (Subject: many; Verb: admire; Object: Whom [Ram])
Ram, who many admire, likes Shyam.
This sentence is correct.
Ram is the subject
Who refers to the subject.
Who acts as an object in its clause “who many admire” (Subject: many; Verb: admire; Object: Who [Ram])..
Grammatically, Whom is an object form of Who and thus always acts as an object. ho is more flexible – Who can act as a subject or an object in its clause. However, there is one way Who cannot be used, i.e., as an object of the preposition when the preposition appears right before Who.
For example:
Indian cricketers, one of whom is a billionaire, are expected to arrive shortly.
Here, “whom” is the correct pronoun since we need an object of the preposition “of”. The following sentence is incorrect since Who cannot act as an object of a preposition.
Indian cricketers, one of who is a billionaire, are expected to arrive shortly.
On the other hand, if we separate Who from the preposition and put the preposition at the end of the clause, we can have Who as even the object of a preposition. For example:
I recently met George’s brother, who I went to school with.
The meaning of the Who-clause is: I went to school with George’s brother. (I – subject; went – verb; George’s brother – object of the preposition ‘with’)
Since Who refers to George’s brother and ,meaning-wise, George’s brother is the object of the preposition ‘with’, Who acts as an object of the preposition ‘with’ in its clause.
This use is CORRECT. Who can act as an object of the preposition as long as the preposition doesn’t appear before Who.
Bonus Info: Who and Whom can NEVER create an Independent Clause; they always create a Dependant Clause. Of course, the dependent clause could be a part of some Independent Clause.
You can read more about the relative pronouns on the following links:
1. British Council
2. Cambridge Dictionary
3. Merriam Webster
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