Sevgi, about whom I’ve written before, asked me this. The conclusion that a comma is “half a breath” was hers, not mine.
You know
A full stop stops.
You’ve said your piece.
You’ve shut your mouth.
But sometimes, wait, there’s more:
An afterthought
A subordinate clause
(Don’t worry about what that is just yet.
It’s only something else you haven’t met.)
And so you do not stop,
But you pause.
Take half a breath,
Before you carry on
Towards another
Full
Stop.