Add or edit words in a spell check dictionary - Microsoft Support
Add, edit, or delete words in a custom dictionary. To quickly add a word to a your default dictionary, right-click the word in a document, and select. To edit a word, delete it, and then add it with the spelling you want. To save words by default to this custom dictionary, see.
Check spelling and grammar in a different language
On the Review tab, go to Language. Choose Language > Set Proofing Language, and then select Detect language automatically. Set the proofing language to check spelling in different languages within a single document. Get suggestions in different languages with Editor.
Change the capitalization or case of text - Microsoft Support
To change the case of selected text in a document, do the following: To capitalize the first letter of a sentence and leave all other letters as lowercase, select Sentence case. To exclude capital letters from your text, select lowercase. To capitalize all of the letters, select UPPERCASE.