In spoken discourse, we can usually predict when our conversational partner is about to finish a turn by listening to their intonation. This is not always successful, however, as demonstrated by the following clip in which a TV host assumes that the reporter has finished his lines when in fact he has more to say.  

JC (Jo Coburn) predicts the end of the AF’s (Adam Fleming) turn in lines 01 & 02 below. The evidence for this is falling intonation on the units and the micropause at the end. Research shows that we signal the end of a turn with falling intonation and low key.

01 AF: all pretty controversial
02     all pretty complicated (.)

03 JC: right (.) well [let’s erm
04 AF:                [when it comes to finishing

External link to audio clip

Intonation Pattern

Given this evidence, the host JC assumes she can take back the floor in line 03. However AF continues in 04 and there is brief overlap between the two conversational participants. Note how AF’s next line 04 is high key. This signals the start of a new paragraph (paratone).

The conversational partners then act to repair the discourse and JC eventually hands back the floor to AF so that he can finish his turn.

AF: [oh sorry
JC: [xxx

JC: [oh no you go on sorry
AF: [I was gonna say something about fishing as well

JC: I- I thought you [paused there for a moment
AF:                  [erm

JC: so I wasn’t sure
   go on to finishing
AF: hh erm the EU wants a long term

This is a small example of using intonation in turn completion and shows how we micro-manage our conversation through a number of prosodic cues.

Politics Live, BBC, 13th March 2020