Working with PTC Mathcad Prime > Spell Check > About the Spell Check Proofing Language
  
About the Spell Check Proofing Language
In PTC Mathcad Prime 6.0.0.0 or later, you can check the spelling of text regions in your worksheet.
The default proofing language is English (United States). If you want to check the spelling of non English text, then you must first install the language pack for that language on your computer. To see the list of available proofing languages on your computer, click Text Formatting > Spell Check > Proofing Language.