fix grammar

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

doc/guides/language.md

@@ -373,7 +373,7 @@ function return is supported.
 
 ### Array and String Subclasses
 
-`Array` and `String` does not support instance variables to reduce memory.
+`Array` and `String` do not support instance variables to reduce memory.
 This means subclassing `Array` or `String` and adding `@fields` will raise an error.
 
 ### Operator Overriding

doc/limitations.md

@@ -111,7 +111,7 @@ Syntax error
 
 ## Operator modification
 
-Operators on some of the primitive classes cannot be overriden, as they are
+Operators on some of the primitive classes cannot be overridden, as they are
 optimized in the VM.
 
 ```ruby