What spelling correction actually does

Spelling correction in Word is a feature that finds words it does not recognize and suggests alternatives. It does not fix your spelling automatically — it flags the word with a red underline and waits for you to decide whether to change it. You can accept the suggestion, ignore it, or add the word to your dictionary so Word stops flagging it in the future.

Word compares every word you type against its built-in dictionary. When it finds a word that is not in that dictionary, it calculates which real words are closest to what you typed — usually by counting how many letters are different. If you typed "recieve" instead of "receive", Word suggests "receive" because it is only one letter away. If you typed something so far off that no close match exists, Word may offer no suggestion at all.

This is different from autocorrect, which silently replaces certain words as you type. Spelling correction shows you what it found and lets you choose.

Key Takeaways

  • Red underlines mean Word does not recognize the word, not that it is definitely wrong — proper nouns and technical terms often get flagged.
  • Right-click a red-underlined word to see Word's suggestions and choose whether to accept, reject, or add it to your personal dictionary.
  • Adding a word to your dictionary stops Word from flagging it in future documents, which is useful for names, brand terms, and specialized vocabulary.
  • You can turn spelling correction on or off entirely, or set it to check only when you ask it to, rather than as you type.

How to use the red underline suggestions

When you see a red wavy underline under a word, right-click it. A small menu appears with up to three options at the top: suggested corrections. Click any suggestion to replace the word when ready. If none of the suggestions is what you meant, click elsewhere to close the menu and type the correct word yourself.

Below the suggestions, you will see "Add to Dictionary" or "Ignore All". Click "Add to Dictionary" if the word is correct but Word does not know it — this is the right move for your own name, your company name, or technical terms you use often. Click "Ignore All" if you want Word to stop flagging this word for the rest of this document only. The next time you open a different document, Word will flag it again.

The difference between "Add to Dictionary" and "Ignore All"

"Ignore All" is temporary and document-specific. It tells Word: stop flagging this word in this file, but I am not saying it is a real word. The next document you open will not remember this choice.

"Add to Dictionary" is permanent and applies everywhere. It tells Word: this is a real word, add it to my personal dictionary. From that moment on, Word will not flag it in any document on your computer. This is the right choice for words you use repeatedly — your name, your job title, the name of your organization, or technical terms in your field.

If you add a word by mistake, you can remove it later. Go to File > Options > Proofing > Custom Dictionaries, select the dictionary, click "Edit Word List", find the word, and delete it.

Turning spelling correction on, off, or to manual mode

By default, Word checks spelling as you type and shows red underlines. If you find this distracting, you can change it. Go to File > Options > Proofing. Look for the section called "When correcting spelling in Microsoft Office documents".

You will see a checkbox labeled "Check spelling as you type". Uncheck it to turn off the red underlines entirely. Word will still check your spelling if you ask it to — go to Review > Spelling & Grammar to run a check whenever you want.

You can also check the box "Hide spelling errors" if you want the feature on but do not want to see the red lines while you work. The spelling errors are still there; you just will not see them until you run a manual check.

Why Word flags words that are actually correct

Word's dictionary is large but not infinite. Proper nouns — names of people, places, and organizations — are usually not in the dictionary, so Word flags them. Technical terms, slang, brand names, and words from other languages also get flagged often. This is not a mistake on Word's part; it is just how the feature works.

If you use a word repeatedly and Word keeps flagging it, add it to your dictionary. This is especially useful if you write about a specific field or work for an organization with a particular name or terminology. After you add five or ten words, the red underlines will stop interrupting your work.

What spelling correction cannot do

Spelling correction only catches misspelled words. It does not catch words that are spelled correctly but used in the wrong place — "their" instead of "there", or "its" instead of "it's". For that, you need grammar checking, which is a separate feature. You can turn on grammar checking in the same Proofing menu; it shows blue underlines instead of red ones.

Spelling correction also does not know the context of your document. If you type a word that is not in the dictionary but is spelled correctly according to English rules, Word will flag it. You have to decide whether it is actually a word or a typo.

Frequently Asked Questions

Can I undo adding a word to my dictionary?

Yes. Go to File > Options > Proofing > Custom Dictionaries > Edit Word List. Find the word you added, select it, and click Delete. The next time you type that word, Word will flag it again.

Why does Word suggest words that do not make sense?

Word suggests words based on how close they are to what you typed, not on what would make sense in your sentence. If you type "teh", Word suggests "the" because it is one letter away. If you type something very different from any real word, Word may have no good suggestion.

Does spelling correction work the same way in Outlook and Excel?

The feature works the same way, but you turn it on and off in the same Proofing menu for all Microsoft Office programs at once. If you turn it off in Word, it turns off in Outlook and Excel too.

What if I want to check spelling only once, not as I type?

Uncheck "Check spelling as you type" in File > Options > Proofing. Then whenever you want to check, go to Review > Spelling & Grammar. Word will scan the whole document and show you every flagged word at once.

Can I add multiple words to my dictionary at once?

No, you have to add them one at a time by right-clicking each one and selecting "Add to Dictionary". If you have a long list of technical terms, this takes a few minutes, but you only do it once.