Reply To: GREP to replace straight double quotation marks

I know this is an old post, but I have a somewhat related question. I have several manuscripts that were originally typeset in Australia. For dialog, single quotes are used. I need to change all the single quotes to double for American readers. Is there any GREP that you know of that will accomplish that. I obviously don’t want to replace all single quotes, as some are meant to be apostrophes. Any advice would be appreciated. Thank you.