How do I stop voice verbalizing letters I am texting?

Hello,

you may enable VoiceOver in Accessebility, that feature will speaks everything is on the screen.

To turn VoiceOver on or off, do any of the following:

• Go to Settings  > Accessibility > VoiceOver, then turn the setting off.
• Use Control Center if you’ve added it there.
• Use Accessibility Shortcut if you’ve set it up.

Also here is the user guide

Turn on and practice VoiceOver on iPhone – Apple Support (UK)

kind regards,

How I’m the jack do I get this womanto Quit telling me capital I or a whole word

Go to Settings>Accessibility>Spoken Content>Typing Feedback and turn off everything on that page.