Many english speakers mix up ‘who’ and ‘whom’. do you know which of these sentences is incorrect? a. i have two brothers, one of whom is a scientist. b. with whom did you go skiing today? c. who's going to the park today ? d. okay, who did you agree with ?

From the list, the incorrect sentence is: 'Okay, who do you agree with?. Instead of using who, it should be using whom. The correct sentence would be ' Okay, whom do you agree with?

Who and whom are pronouns. 'Who' refers to the subject of the sentence and 'whom' refers to the object of a verb or preposition. If you in doubt whether who or whom, you can substitute who with she, he, I or you. Replace whom with him or her. For example:

1. I have two brothers, one of whom is a scientist.  

We can replace the word 'whom' in this sentence with them NOT they, the sentence would be' I have two brothers, one of them is a scientist, so the sentence is correct

2. Who's going to the park today?

We can replace the word 'who' with she or he, so the sentence is correct.

3. With whom did you go skiing today?

This question is asking the object not subject.  

Actually, not many people using whom in casual conversation or writing. Here another example in using who and whom:

1. Who wrote this letter?

2. Whom should I vote for?

3. Who is that girl?

4. Annie is the one who wants to go.

5. This is the boy whom I told you about.

Keywords: using who or whom, the difference between who and whom

this is b. how railways dealt with people riding the trains without paying

motion can be transfered from one object to another by having an objetct in motion push or hit it