The Set Language dialog allows the user to select the languages to use for spell checking. It is located in the Proofing group in the Review Tab.

 

 

The following dialog appears:

 

 

The checked languages will be the ones used for spell checking.

To start spell checking, click on the Check Spelling button or press Ctrl+F7. This action will select the next misspelled word from the current caret position and show suggestions for correcting it.