When writing an essay when is the proper time to use whom over who?

Answer and explanation:

Even though similar, the pronouns "who" and "whom" are not the same.

"Who" should be used to refer to the subject of a sentence, while "whom" should refer to the object of a verb or preposition. Use the following trick to help you determine when to use which:

if you can substitute it for a subject pronoun (he, she...), then it should be "who": He is the scientist. The scientist (he) discovered new uses for this chemical element. ---> He is the scientist who discovered new uses for this chemical element.if you can replace it for an object pronoun (him, her...), it should be "whom": He is the scientist. The committee awarded the scientist (him) with a Nobel Prize. ---> He is the scientist whom the committee awarded with a Nobel Prize.