Nay, I have actual conversations in my sleep. Coherent enough that I can easily be mistaken for being awake - except when I am asserting something that is clearly not so.
Example. Last night. I went to bed first, being terribly worn out from my day. Adam came upstairs an hour or so later and turned out the light.
Me, irritated: "I was reading."
Adam: *looks at clearly-sleeping 'song with no book anywhere in sight* "No. You were sleeping."
Me: "No. I was reading."
Max: *jumps onto the bed*
Me: "Hiiiii, Max." *snuggles Max*
Adam: *thinking it's over, gets into bed and drifts off somewhere near sleep, where he hears -*
Me, muttering quietly: "...was reading."
I also at some point told him to put a bookmark in the nonexistent book, which I think was totally reasonable.