When talking on a person can I always replace the relative clause "that" with "whom"? I am pretty confused with the using of "whom".
For example:
1) The teacher that (also who) was here - now is there. > The teacher whom was here - now is there.
Example No.2
2) The waiter who gave you the food - is in the kitchen now. > The waiter whom gave you the food - is in the kitchen now.
example No.3
3) Those guys who you talked to, now are looking for you. > Those guys whom you talked to, now are looking for you.