For me, English is a sense of humor. Whenever I get confused if I should use "who" or "whom" when writing essays, I recall one sentence from my memory: A likes B whom C hates. With that sentence, I realize that I should use "whom," not "who," if I wanted to write, for example, "students whom the principal awarded." I also recall a couple of sentences when I`m not sure about the tense―"When I came in, John had eaten his shoes" and "When I came in, John ate his shoes." Then I distinguish the difference between the two sentences...