fix typo

Author: tbrowder

doc/Language/grammar_tutorial.pod6

@@ -13,7 +13,7 @@ perfectly.
 
 =SUBTITLE When Would I Use Grammars?
 
-Grammars are great at taking stings, trying to make sense of them, and then saving them into a data structure you can actually work with. If you have strings of some kind that you need to bring order to, or interpret, grammars give you some great tools to make it easier.
+Grammars are great at taking strings, trying to make sense of them, and then saving them into a data structure you can actually work with. If you have strings of some kind that you need to bring order to, or interpret, grammars give you some great tools to make it easier.
 
 Your string might be a whole file that you need to break into sections. Or
 perhaps line by line. Maybe you have a protocol like SMTP you're working with,