I can't figure out how or why Outlook 2011 is doing this, but I've checked the MS Office dictionaries and I don't see it. But what is happening is that when I type in dont or don't,  the autocorrect is correcting it to say
don't'    the same with couldn't becoming couldn't'  

Note the extra apostrophe after the t '  



Where can I find this incorrect auto correct and stop it? 
Thanks
Jeff