Siri is pretty good with simple dictation, but when it comes to changes in punctuation and line spacing, it needs a bit more direction. Luckily, this virtual assistant does exactly what you want it to if you know what to say.
Siri recognizes all of the following symbols and commands: open/close parenthesis, em dash (the long dash), copyright, dollar, cent, degree, percent, asterisk, ampersand, all caps, all caps off, cap (which capitalizes a single letter), registered, and more. So if you wanted to dictate an email without making any manual changes, you would say something like this:
“cap Dear Siri comma cap, It is my regret to inform you that cap I will have to reschedule our meeting today period.”

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Correct Siri's punctuation easily with verbal commands.