[writing help] 1st, 2nd, 3rd Person

First Person corresponds to "I, me"

Second person to "you"

Third Person to "him, her"

So, I would say the dialogue (my spelling) is mostly in the second person.

But wouldn't the whole context be in 3rd person in the 1st and 2nd example?

Yes, I see what you mean, and I think you are correct. It may make a difference when the quotation marks are missing.

Roberta is our resident expert. Also Clary, who is travelling at the moment. I will try to raise them. The question is not a familiar one to me.

Unfortunately the PM (personal messaging) facility has been disabled for now. I'll try a different route.

I'm not sure I understand the question."You gave me this red jacket for my birthday," said John. The author of the sentence has described the speaker in the 3rd person (John). But, in speaking, the quote itself is in the first person (me), referring to a 2nd person person (you). So, what, specifically, is the question?