Word 2016 offers on-the-fly grammar checking. Mark Twain once referred to English spelling as "drunken." If that's true, English grammar must be a hallucination. It's just like having your eighth-grade English teacher inside your computer — only it's all the time and not just during third period.
Word's grammar checker works like the spell checker. The main difference is that offenses are underlined with a blue zigzag, such as the one shown (although the zigzag looks gray). That's your hint of Word's sense of grammatical justice. Even then, the offense is most likely mild and, given the illusionary nature of English grammar, can probably be ignored.
To address a grammar issue, right-click the blue-underlined text, as shown. Use the pop-up menu to discover what's wrong or to choose an alternative suggestion. You also have the option to ignore the error.
The most common source of grammatical woe in English is verb agreement, or matching the subject to the correct verb.
The grammar checker is excellent at spotting two spaces between words when you need only one space. It's not so good at spotting fragments.
You may see false grammar errors when using Word's revision-tracking feature while the No Markup setting is enabled. Reveal all the revision marks to see what's up.
You can customize or even turn off grammar checking.
