[#3336] Minor tweak

Author: weaverryan

reference/forms/types/options/compound.rst.inc

@@ -4,5 +4,5 @@ compound
 **type**: ``boolean``
 
 This option specifies if a form is compound. This is independent of whether the
-form actually has children. A form can be compound but don't have any children
+form actually has children. A form can be compound but not have any children
 at all (e.g. an empty collection form).