The change of tone into rising here having the effect that the statement now sounds incomplete, as if the speaker is about to add something else (like, what should I do now? Can you help me?)
In other words, the rise in this case ‘means’ incomplete information and depends on further information for it to make sense.
Coupled with rise, the falling tone ‘means’ that the information can be understood independently of any other information and can be considered as major information. It is the speaker who decides. The speaker knows what information they wish to provide and the status of each piece of information is indicated by their choice of tone.
