I don't think you can teach conversational skills specifically - but I think a person can become more comfortable in their own skin and more confident, and in doing so can be more natural in conversation (and public speaking in general).
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Law and Order: Gotham - “In the Criminal Justice System of Gotham City the people are represented by three separate, yet equally important groups. The police who investigate crime, the District Attorneys who prosecute the offenders, and the Batman. These are their stories.”