These are some great links to help children of all ages with conversational speaking The first link is just an abstract, but it describe a study which found the best way to stimulate grammatical complex sentences from children was to involve them in making stories. Talking while engaging in free play, resulted in the most words, but the sentences or comments were much briefer.
For children with significant language impairments, a little practice with all three might be good practice. The significant language challenge of back-and-forth conversation was also underscored in this report. Children witha significant degree of anxiety over speech difficulties may first gain confidence with speaking during play, then progressing onto more challenging tasks like thinking up a story, or talking about a favorite subject.
Different Ways to Stimulate Verbally Challenging Conversation
Apraxia Articles Index - Speech Therapy, Evaluation, Insurance, Education, and Other Topics
Not Talking Yet?
The Talking Page