Why is macbeth both excited and fearful after hearing the witches prediction about his future ?

I would need more info to have a good answer this, but I would say knowing the future is a big responsibility.  Responsibility can come with fear, but knowing what might happen is kinda cool/exiting.

Singular third person pronouns are “he,” “she,” “it,” “his,” “hers,” “him” and “her,” and third person plural pronouns are “they,” “them” and “their.” the number of people to which you are referring should always match the pronoun you choose (“he” to refer to one male, “they” to refer to more than one male).