Word Spell Check Not Working — What Causes It & How to Fix It

What Does This Error Mean?

Word spell check stops working when it's been turned off in settings or the document language is wrong. If Word is checking English text but the language is set to French, it won't find English errors. All fixes take under two minutes.

Affected Models

Microsoft Word 2019
Microsoft Word 2021
Microsoft 365 Word
Word for Windows

Common Causes

Spell check is turned off in Word's proofing options
Document language is set to a different language than the text (so spell check looks for the wrong errors)
Text is marked as 'Do Not Check Spelling' — a setting that hides text from the spell checker
Typos were added to the custom dictionary, so Word now thinks they're correct words
Word's proofing tools are damaged and need an Office repair

How to Fix It

Go to File > Options > Proofing and make sure 'Check spelling as you type' is checked.

This checkbox gets unchecked sometimes during Office updates — it's the most common cause of missing red squiggles.
Select all text with Ctrl+A, then go to Review > Language > Set Proofing Language and choose the correct language.

If your document is in English but the language is set to Spanish or French, Word will check the wrong language and find nothing wrong.
In the Set Proofing Language dialog, make sure 'Do not check spelling or grammar' is NOT checked.

This hidden option silences spell check for any selected text — it's easy to turn on by accident.
Clear your custom dictionary: File > Options > Proofing > Custom Dictionaries > Edit Word List, then remove any wrong words.

If you ever clicked 'Add to Dictionary' on a typo, Word will never flag that word as wrong again.
Repair your Office installation: go to Control Panel > Programs > Microsoft 365 > Change > Quick Repair.

If spell check is broken in Word but everything else is fine, a Quick Repair usually fixes it in a few minutes.

When to Call a Professional

Spell check issues are easy fixes you can do yourself. All fixes are inside Word or Windows — no IT help needed.

Frequently Asked Questions

Why does Word underline everything in red even when it's spelled correctly?

The proofing language is set to the wrong language. Select all text, go to Review > Language > Set Proofing Language, and choose the correct one.

Can I re-enable spell check for just one section of my document?

Yes — select only that section, go to Review > Language > Set Proofing Language, and uncheck 'Do not check spelling or grammar'. Spell check will work on that section again.

I accidentally added a misspelling to the dictionary — how do I remove it?

Go to File > Options > Proofing > Custom Dictionaries > Edit Word List. Find the wrong word in the list and click Delete.