Typing in all caps is never necessary. Using capitalization is important to be grammatically correct; typing a sentence in ALL CAPS is considered shouting and generally frowned upon as rude in online conversation. Unless you are indeed having a shouting match over email or instant message, you should always use correct capitalization — you know, capitalizing the first word of the sentence, when using pronouns, and so on. Unfortunately, there are times when you need to convert a paragraph into lowercase when someone else has incorrectly typed a document in all caps — or, perhaps, in AlTerNatIng CaPs (because either the other person thinks they are 13, or they really still are 13).
If you are editing or creating a document in one of the programs in Microsoft Office, including Microsoft Word, you can change all caps to lowercase using the shortcut key combination Shift + F3. This will allow you to change a paragraph that is in ALL CAPS or AlTerNatIng CaPs into sentence case, or all lowecase. For example, to transform:
“THIS IS A SHOUTING SENTENCE! IT’S AWFUL!”
hit Shift + F3 once, and you will get:
“this is a shouting sentence! it’s awful!”
and hit Shift + F3 twice:
“This is a shouting sentence! It’s awful!”
Keep in mind that the above phrase was already grammatically correct — had you not used the proper contraction for “it is” and instead used “ITS” the shortcut key Shift + F3 will not have corrected it for you when you used the shortcut to change all caps to lowercase. Shift + F3 does work well for just changing caps to lowercase or to sentence case, especially with large chunks of text such as paragraphs, emails, or instant messages that are difficult to read. This shortcut also only works in Microsoft Office, so you can not use Shift + F3 in email programs like Gmail, Yahoo! or Hotmail, or when instant messaging. You can always open Microsoft Word, though, and copy and paste the offensive all-caps message to change all caps to lowercase for readability. And then perhaps offer the offender who typed the message in all caps a lesson on Internet and email etiquette.