It's frustrating when you're typing a document in Word and it underlines correctly spelt words, suggesting you've got it wrong. The classic example is when you're using UK English spellings, but Word is set to US English and it wants to change favourite to favorite and centre to center. It might even auto-correct these 'typos'.
See also: Microsoft Office 2013 review
Usually, the solution is simple: change the default language in Word's settings. However, there may be other issues which we'll discuss later.
How to change the language in Word 2007, 2010 and 2013
Launch Word and click the Review tab. Click the Language drop-down and choose Language Preferences. Chances are, you'll see at least two languages listed in the Choose Editing Languages section. Click on English (United Kingdom) or whichever language you want to be the default, and click the Set as Default button on the right.
If you like, you can remove any languages you don't use.
You can separately set the proofing language, which is the other option under the Language drop-down menu. Again, set this to the language you want to use.
If you have Word 2003, click on Tools, Language, Set Language. Now select English (UK) and click Set As Default. A pop-up box will warn you that changes will affect all documents created with the Normal.dot template.
If you need to type in two different languages, say English and Spanish, be sure to tick the Detect language automatically box.
Conversely, if you're having problems where the dictionary switches unpredictably to another language and won't accept spellings in the language in which you're typing, make sure the 'Detect language automatically' box is unticked.
Word settings aren't retained
Sometimes, your settings aren't retained and when you re-open Word, it has changed back to a different default language.
This can happen when you have more than one keyboard layout configured on your computer. In Windows XP, go to the Control Panel and search for Keyboard.
Double-click it. In Windows 7, click Region and Language in the Control Panel, then Keyboards and Languages, and Change keyboards…
In Windows 8's Control Panel, click Clock, Language and Region, then Change input methods.
Regardless of Windows version, check that your main language is both installed and set as the default (the language at the top of the list is your 'primary' language, so click the Move up / Move down buttons to correct the order). Again, you can remove languages that aren't required.
You might also be interested in: Speedy shortcuts for Microsoft Word