Feeling Lazy, Alittle Help, Please.

Can someone please tell me the correct format?  I've become confused over this issue and "spelling and grammar checker" and I are about to go toe-to-toe.  When and where should the apostrophe be used in relation to "its?"  I always thought that the apostrophe was used only in the possessive as in "it reared it's ugly head."  "Spelling and grammar checker" seems to feel otherwise.  However, it also flaged when I tried to use the apostrophe in the contraction, as in "its difficult to understand."  I seem to remember AP English, like the whispy tendrils of a fleeing ghost -- meaning, its all drifting away with the passage of years (many, many years). 

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2 Responses Mar 8, 2010

No prob, glad i could help! :)

"it's" = it is / it has<br />
"its" is a possesive.. <br />
<br />
so.. "it reared its ugly head" and "it's difficult to understand". :)