These idioms will help you describe talking and communication.
Talk
talk nineteen to the dozen = talk fast: "She was so excited that she was talking nineteen to the dozen."
talk the hind legs off a donkey = talk without stopping: "She can talk the hind legs off a donkey!"
talk something through / over = to discuss something: "Before we decide anything, I think we ought to talk it through."
talk something up = to make something appear more important: "She really talked the idea up, but I don't think that everyone was convinced."
talk someone into doing = to persuade someone: "He talked her into buying a new car."
talk someone through something = give step-by-step instructions: "She talked him through the procedure."
talk down to = talk in a condescending way: "Don't talk down to me! I understand you perfectly well."
talk back = respond to someone in authority in a rude way: "Don't talk back to your mother!"
This is similar to back chat: "I don't want any back chat from you!"
talk under your breath = talk quietly so that nobody can hear you: "They talked under their breath in the meeting."
talk rubbish = not to speak logically: "He talks complete rubbish sometimes!"
Also talk through your arse (British slang and quite rude): "You're talking through your arse again. You know nothing about it!"
talk at cross purposes = when two people don't understand each other because they are talking about two different things (but don't realise it): "We're talking at cross purposes here."
talk around the subject = not get to the point: "He didn't want to say they were in danger of losing their jobs, so he talked around the subject for half an hour."
talk highly of someone = praise someone: "He talks very highly of you!"
to give someone a talking-to = when you talk to someone because you are angry with them: "His boss gave him a real talking-to yesterday!"
talk to yourself = to speak to yourself, maybe because you are concentrating on something: "Are you talking to yourself again?"
straight talking = honest words: "I want some straight talking around here!"
talk shop = talk about work in a social situation: "Whenever I go out with my colleagues, we always end up talking shop."