How are people responding with normal size text?  I was able to do it until recently but now when I quote I end up with big a bigger font. 

Notice the darker grey bar to the right of the quoted text. That signifies a quote. You need to make sure your response starts after the quote. You can hit the down arrow key to jump to the next line below the quote. If you just hit enter then type, your text will be an extension of the quote and share the larger font size. There's currently no way to separate multiple quotes in a single post that I'm aware of. 

Ok, I got it to work this time, tried to use down arrow before so I don't know why it did not work.  Those bars aren't displaying right for me.  They were sort of there for a second as I scrolled down, but are gone now that I've started typing...