Fix a word

docs/diagnostics/5006.md

@@ -85,7 +85,7 @@ It reports overloaded types as the following:
 
 Unsolved record types that may have other fields, which often arise with usages of `#` selectors, will be reported as record types with an extra `...` row.
 
-Automatically generated type variable names will use `?` as the prefix, instead of `'` which is used user-written type variable names.
+Automatically generated type variable names will use `?` as the prefix, instead of `'` which is used for user-written type variable names.
 
 If Millet encounters an invalid expression, like a variable that was undefined, it will report the type `_`. It will also report `_` for unsolved type variables.