Talk vs speak

Dear teachers,

Please tell me the difference btw “talk” and “speak” in:
a. May I speak to him?
b. May I talk to him?



Talk to is essentially have a conversation with. Speak to is principally say to in the sense of directing words to without necessarily expecting the other person to say anything in return.

As the Queen made her way through the crowd, she spoke to one or two people and talked to several of the children.