Improved explanation

Author: molecules

doc/Language/faq.pod6

@@ -302,7 +302,9 @@ not. The C<s///> operator works on a variable, into which it puts a newly
 created string object. Likewise, C<$i++> works on the C<$i> variable, not
 just on the value in it.
 
-So, you cannot do the following, because they try to change the original C<Str>:
+Knowing this, you would not try to change a literal string (e.g. like 
+C<'hello' ~~ s/h/H/; #doesn't work>), but you might accidentally do
+something equivalent using `map`:
 
     my @foo = <hello world>.map: { s/h/H/} ; # dies with
                                              # Cannot modify an immutable Str (hello)
@@ -312,8 +314,7 @@ So, you cannot do the following, because they try to change the original C<Str>:
                                                             # the following candidates match the type but require
                                                             # mutable arguments: ...
 
-But if you use an operator that returns a new value instead of changing the 
-original, you can acheive your goal:
+Instead, use an operator that returns a new value instead of changing the original:
 
     my @foo = <hello world>.map: { .subst('h','H')}; # ['Hello','world']
     my @bar = <hello world>.map: { .uc };            # ['HELLO','WORLD']