The sentences that need to be corrected are: You are eating dinner with whom?
For whom did you make this birthday cake?
The correct sentences should be:
Please, note that others are correct.
'Who' and 'Whom' are known to be pronouns. 'Who' is actually used to refer to the subject of the sentence. 'Whom' is used to refer to the object of a verb in the sentence.
We can see in the above corrected sentences, 'who' is acting as a subject of the sentence.
Learn more about pronouns on https://brainly.com/question/1240856