Grammar check is not catching error in "it won't go threw". Why?

[LB1]

The above sentence is grammatically incorrect, but Office is not catching the
error. Do I need to change my settings?

 

[garfield-n-odie [MVP]]

See http://support.microsoft.com/kb/290943/en-us "Frequently
asked questions about grammar proofing in Word 2003 and Word
2002". I think items 7 and 8 in the "More Information" section
apply to your situation.