Noun (human) + [who + finite verb].
Mr. Brown who came yesterday like to see you again.
Who: connector/ subject, Came: transitive verb
Noun (human) + [whom + subject + finite verb]
The girl whom we saw in the park had been in a terrible accident before.
Whom: connector/object, Saw: intransitive verb,
Noun (non-human) + [which + finite verb]
The table which is broken cannot be fixed today.
Noun (non-human) + [which + subject + finite verb]
The table which you bought at the antique fair is very nice.
I am tired of all the trouble which you are causing.
For (teem, group, staff, …) “which” is used as a connector.
The committee which started the argument is closed now,
The committee which you joined is not appropriate for you.
Noun (time) + [when + sub + finite verb (intransitive)] (The noun should be
the time in which the verb happens)
Do you remember the day when Sam arrived?
I enjoy the day when I am free.
Spring is the season when all flowers blossom.
If the noun is not the time in which the verb happens, “when” will replace with
I like the day which is not so hot.
Spring is the season which I like best.
Noun (place) + [where + subject + finite verb (intransitive) (The noun
should be the place in which the verb happens.).
The city where I was born is now famous for its high crime rate.
The city which I love most is Tehran.
The city which is located in the north is Rasht.
The city which I suggest you to visit is Isfahan.
It is also correct to replace “where” with “in which” or “which….in”.
Noun (place) [where/in which/which in/ that….in + subject+ finite verb.]
Do you know the city that I was born in.
Noun (reason) [why + subject + finite verb] (The noun should be the reason of
Do you know the reason why I was arguing?
Noun (person owner) [whose + noun (owned) + finite verb]
The chairman whose committee won the election, had been very
prosperous last year.
Noun (non-person owner) [noun (owned) + of which + finite verb]
The table the leg of which is broken must have been very expensive.
“Who” is always subject and cannot be omitted.
“Whom” is always object and can be omitted.
“Which” as a subject cannot be omitted but as an object can be omitted.
“When” can be omitted.
“Where” cannot be omitted but can be replaced by in which/that …..in or
“Why” can be omitted.
“Whose” cannot be omitted.
“Of which” cannot be omitted.
“That” can be replaced by Who, Whom and Which and can be omitted.
“That” never comes with coma.
She is the person to whom I talked.
She is the person whom I talked to.
He is the person on whom I rely.
He is the person whom I rely on.