Don't worry about your command of the English language - we are here to help.
I've done some testing. I set my default read and view font to text. I then opened an HTML message, selected text in it and then right-click and select Print - From the print dialog screen I selected, under Page Range, "selection" and my selection was printed. If my default read and view font is set to HTML I get the same results.
However, I am unable to print selected text from a text based e-mail.
Let me do some more testing on a newer client and I will post back my findings.