Do you speak more than one language? Microsoft Office 2013 supports the use of multiple languages in proofing, writing, and spell-check. Setting it up hasn’t changed much since Office 2010, so this shouldn’t take long to walk through.
In any Office app, open the File ribbon.

From the File menu click the Options button.

In the Options window click the Language tab.

Use the drop-down menu titled “Add additional editing languages” to select the language you prefer and then click Add.

That’s it! It’s added. You can now use your newly added editing language to spell check for words written in that language.
Keep in mind that there’s a good chance your language won’t be supported as usually only English and Spanish are the defaults. If this is the case you’ll need to download and install the Office 2013 Preview Language Pack.

For more information about setting up language-specific keyboard layouts or Not Installed languages, see this article.

I hope it offers español, not espanol.
Wasted 2 days with level 2 technicians at Microsoft Office Research Team who tried to find out why my PPT 2013 Spanish spell checker kept rerouting to English dictionary instead of the Spanish editing language selected. I made all the language choices and they even me install the entire Spanish language pack and make everything in Spanish on my computer and the spell check still defaulted to English. Then after the 2 days they informed me that Microsoft only has a working Spell checker in Spanish in Word and Outlook. Anyone know of a fix? What can I do short of waiting for to figure it out. I have a Surface Pro, Windows 8 and need this functionality in PowerPoint 2013. Thanks, Bess