1) DON’T SAY: Who did you visit?
SAY: Whom did you visit?
(2) DON’T SAY: Whom visited you?
SAY: Who visited you?
RULE: In English, “who” is a subjective pronoun as he, they.“Whom” is an objective pronoun as him, them. So, when the person you are referring to does the action, use who. When he receives the action, use whom.
In the first sentence, ‘you‘ is the subject visiting the person. Rightly then, whom should have been used because it receives the action of that one. Substituting ‘him‘ for ‘whom‘, the sentence will read: You visited him( whom)? Which is correct. By contrast, using ‘who’ will make the sentence read, You visited he( who)? Which is wrong!
In the second sentence, ‘whom‘ is incorrect because ‘you‘ is now the object receiving the action of the person been referred to;hence, who should have been used.
Substituting ‘he‘ for ‘who‘, the sentence reads: He(who) visited you? On the contrary, using ‘whom‘ will make the sentence read: Him(whom) visited you? Which is glaringly incorrect.
1. It was he whom we want to see. ( not who) [ We want to see him( whom)]
2. Whom were you referring to? ( not who) [ You were referring to him(whom)?]
3. These were the robbers who broke into our house last year. ( not whom) [ They( who) broke into our house?]
4. Who told you I wasn’t there? ( not whom) [ He( who) told you?]