Due to an injury in my shoulder, I'm relying more and more on iPhone dictation to write emails and WhatsApp messages. It works like a charm when my words are understood correctly; however, I have been unable to find commands to navigate, corrected misspelled/misunderstood words, and edit partially written messages. 

Are there commands for this? Or is there a way to program them? I don't need very specialized functions. Just navigation and editing.