Microsoft PowerPoint uses a default dictionary to check the spelling of words in a presentation. This dictionary is shared with products such as Microsoft Word and Microsoft Excel. The spelling checker will stop on words that are misspelled or aren't in this dictionary, and you have the option to add the words to a custom dictionary. The custom dictionary is handy for specialty terms, such as medical terms or words that are unique to your work environment.

When you are working in PowerPoint, you can check the spelling of text in dictionaries of other languages as well as in supplemental dictionaries from other programs that you have installed in Microsoft Office.