We have just begun dictation in book 1 for my 10yo son. He did very well, spelling all the words correctly. However, he got much of the punctuation wrong because of where I paused (I was trying not to dictate too much at a time). I can see that some sentences will lend themselves to pausing for punctuation, but not all.
I believe the focus here is on spelling but how important is the punctuation at this point? Is it necessary to have him write it as transcription one day, then dictation the next, simply for the punctuation?
I’ve found it helpful to have my 4th grader read the passage out loud a few times when preparing, with pauses in the appropriate spots for the punctuation. Also, after I dictate the passage I read it as a whole to her so she can hear where the actual pauses are. (She does also write it as copywork first, but needed more help than that to get the punctuation correct.)