There are a few different ways that you can check spelling in Microsoft Word.
First, you can simply run a spell check by clicking on the Review tab and then selecting Spelling & Grammar. This will run a spell check on your entire document and highlight any words that it thinks are spelled incorrectly.
If you want to check the spelling of a particular word, you can do so by right-clicking on the word and selecting Spelling and Grammar. This will open up the spell checker and allow you to choose whether to ignore the word, add it to the dictionary, or change it to the correct spelling.
Finally, you can set Word to automatically check spelling as you type. To do this, go to the File tab and select Options. Under Proofing, click on the Check Spelling As You Type checkbox.