pod: fix assorted grammar mistakes in doc files

pod/perl5180delta.pod

@@ -2291,7 +2291,7 @@ C<PL_glob_index> is gone.
 
 =item *
 
-The private Perl_croak_no_modify has had its context parameter removed.  It is
+The private Perl_croak_no_modify has had its context parameter removed.  It
 now has a void prototype.  Users of the public API croak_no_modify remain
 unaffected.
 
@@ -2340,7 +2340,7 @@ C<mg_length> has been deprecated.
 
 C<sv_len> now always returns a byte count and C<sv_len_utf8> a character
 count.  Previously, C<sv_len> and C<sv_len_utf8> were both buggy and would
-sometimes returns bytes and sometimes characters.  C<sv_len_utf8> no longer
+sometimes return bytes and sometimes characters.  C<sv_len_utf8> no longer
 assumes that its argument is in UTF-8.  Neither of these creates UTF-8 caches
 for tied or overloaded values or for non-PVs any more.
 

pod/perl5200delta.pod

@@ -1529,7 +1529,7 @@ built-in functions not only on aggregate types, but on references to
 them.  The feature was not deployed to its original intended
 specification, and now may become redundant to postfix dereferencing.
 It has always been categorized as an experimental feature, and in
-v5.20.0 is carries a warning as such.
+v5.20.0 it carries a warning as such.
 
 Warnings will now be issued at compile time when these operations are
 detected.
@@ -1971,7 +1971,7 @@ up as /system/bin/sh, and "sh" as /bin/sh.
 
 By default, B<gcc> 4.9 does some optimizations that break perl.  The B<-fwrapv>
 option disables those optimizations (and probably others), so for B<gcc> 4.3
-and later (since the there might be similar problems lurking on older versions
+and later (since there might be similar problems lurking on older versions
 too, but B<-fwrapv> was broken before 4.3, and the optimizations probably won't
 go away), F<Configure> now adds B<-fwrapv> unless the user requests
 B<-fno-wrapv>, which disables B<-fwrapv>, or B<-fsanitize=undefined>, which

pod/perl5260delta.pod

@@ -2622,7 +2622,7 @@ L<[GH #15657]|https://github.com/Perl/perl5/issues/15657>
 
 =item *
 
-Occasionally C<local()>s in a code block within a patterns weren't being
+Occasionally C<local()>s in a code block within a pattern weren't being
 undone when the pattern matching backtracked over the code block.
 L<[GH #15056]|https://github.com/Perl/perl5/issues/15056>
 

pod/perl5340delta.pod

@@ -1300,7 +1300,7 @@ operations.
 
 C<semctl()>, C<msgctl()>, and C<shmctl()> now attempt to downgrade the C<ARG>
 parameter if its value is being used as input to C<IPC_SET> or
-C<SETALL> calls.  A failed downgrade will thrown an exception.
+C<SETALL> calls.  A failed downgrade will throw an exception.
 
 =item *
 

pod/perl5361delta.pod

@@ -68,7 +68,7 @@ interpreter panic; e.g.
 =item *
 
 An C<eval EXPR> referring to a lexical sub defined in grandparent scope no
-longer produces an assertion failures.
+longer produces an assertion failure.
 [L<GH #19857|https://github.com/Perl/perl5/issues/19857>]
 
 =item *

pod/perl561delta.pod

@@ -2642,7 +2642,7 @@ so it was truncated to the string shown.
 
 =item Can't declare class for non-scalar %s in "%s"
 
-(S) Currently, only scalar variables can declared with a specific class
+(S) Currently, only scalar variables can be declared with a specific class
 qualifier in a "my" or "our" declaration.  The semantics may be extended
 for other types of variables in future.
 

pod/perl56delta.pod

@@ -2037,7 +2037,7 @@ so it was truncated to the string shown.
 
 =item Can't declare class for non-scalar %s in "%s"
 
-(S) Currently, only scalar variables can declared with a specific class
+(S) Currently, only scalar variables can be declared with a specific class
 qualifier in a "my" or "our" declaration.  The semantics may be extended
 for other types of variables in future.
 

pod/perldebguts.pod

@@ -961,7 +961,7 @@ grasp of what happens.
 Assume that an integer cannot take less than 20 bytes of memory, a
 float cannot take less than 24 bytes, a string cannot take less
 than 32 bytes (all these examples assume 32-bit architectures, the
-result are quite a bit worse on 64-bit architectures).  If a variable
+results are quite a bit worse on 64-bit architectures).  If a variable
 is accessed in two of three different ways (which require an integer,
 a float, or a string), the memory footprint may increase yet another
 20 bytes.  A sloppy malloc(3) implementation can inflate these

pod/perldebug.pod

@@ -654,7 +654,7 @@ Perl debugger, use a leading semicolon, too.
 X<debugger command, m>
 
 List which methods may be called on the result of the evaluated
-expression.  The expression may evaluated to a reference to a
+expression.  The expression may be evaluated to a reference to a
 blessed object, or to a package name.
 
 =item M

pod/perlfunc.pod

@@ -8375,7 +8375,7 @@ string's internal encoding.
 
 As of Perl 5.39.9 the C</x> default modifier does NOT affect
 C<split STRING> but does affect C<split PATTERN>, this means that
-C<split " "> will produces the expected I<awk> emulation regardless as
+C<split " "> will produce the expected I<awk> emulation regardless as
 to whether it is used in the scope of a C<use re "/x"> statement. If you
 want to split by spaces under C<use re "/x"> you must do something like
 C<split /(?-x: )/> or C<split /\x{20}/> instead of C<split / />.

pod/perlguts.pod

@@ -1293,7 +1293,7 @@ settable with L<< IO::Handle's untaint() method|IO::Handle/"$io->untaint" >>.
 =for apidoc Amnh||IOf_FLUSH
 =for apidoc Amnh||IOf_UNTAINT
 
-The IO object may also contains a directory handle:
+The IO object may also contain a directory handle:
 
   DIR *IoDIRP(io);
 

pod/perlipc.pod

@@ -1445,7 +1445,7 @@ simultaneously copies everything from standard input to the socket.
 To accomplish the same thing using just one process would be I<much>
 harder, because it's easier to code two processes to do one thing than it
 is to code one process to do two things.  (This keep-it-simple principle
-a cornerstones of the Unix philosophy, and good software engineering as
+is a cornerstone of the Unix philosophy, and good software engineering as
 well, which is probably why it's spread to other systems.)
 
 Here's the code:

pod/perlop.pod

@@ -2188,7 +2188,7 @@ A string which is (possibly) interpolated and then executed as a
 system command, via F</bin/sh> or its equivalent if required.  Shell
 wildcards, pipes, and redirections will be honored.  Similarly to
 C<system>, if the string contains no shell metacharacters then it will
-executed directly.  The collected standard output of the command is
+be executed directly.  The collected standard output of the command is
 returned; standard error is unaffected.  In scalar context, it comes
 back as a single (potentially multi-line) string, or C<undef> if the
 shell (or command) could not be started.  In list context, returns a
@@ -3375,7 +3375,7 @@ Bitstrings of any size may be manipulated by the bitwise operators
 If the operands to a binary bitwise op are strings of different
 sizes, B<|> and B<^> ops act as though the shorter operand had
 additional zero bits on the right, while the B<&> op acts as though
-the longer operand were truncated to the length of the shorter.
+the longer operand was truncated to the length of the shorter.
 The granularity for such extension or truncation is one or more
 bytes.
 

pod/perlperf.pod

@@ -588,7 +588,7 @@ systems which provide C<clock_gettime()>.  It can be started and stopped even
 by the program being profiled.  It's a one-line entry to profile C<mod_perl>
 applications.  It's written in C<c> and is probably the fastest profiler
 available for Perl.  The list of coolness just goes on.  Enough of that, let's
-see how to it works - just use the familiar C<-d> switch to plug it in and run
+see how it works - just use the familiar C<-d> switch to plug it in and run
 the code.
 
  $> perl -d:NYTProf wordmatch -f perl5db.pl
@@ -1104,7 +1104,7 @@ completely optimized away, and you can't get much more efficient than that.
 
 =head1 POSTSCRIPT
 
-This document has provided several way to go about identifying hot-spots, and
+This document has provided several ways to go about identifying hot-spots, and
 checking whether any modifications have improved the runtime of the code.
 
 As a final thought, remember that it's not (at the time of writing) possible to

pod/perlsub.pod

@@ -439,7 +439,7 @@ is not important, it may be omitted just as the parameter's name was:
     }
 
 Optional positional parameters must come after all mandatory positional
-parameters.  (If there are no mandatory positional parameters then an
+parameters.  (If there are no mandatory positional parameters then the
 optional positional parameters can be the first thing in the signature.)
 If there are multiple optional positional parameters and not enough
 arguments are supplied to fill them all, they will be filled from left

pod/perlthrtut.pod

@@ -26,7 +26,7 @@ If you have neither, you don't have any thread support built in.
 If you have both, you are in trouble.
 
 The L<threads> and L<threads::shared> modules are included in the core Perl
-distribution.  Additionally, they are maintained as a separate modules on
+distribution.  Additionally, they are maintained as separate modules on
 CPAN, so you can check there for any updates.
 
 =head1 What Is A Thread Anyway?

pod/perlvar.pod

@@ -821,7 +821,7 @@ C<require__before> hooks are called in FIFO order, and if the hook
 returns a code reference those code references will be called in FILO
 order.  In other words if A requires B requires C, then
 C<require__before> will be called first for A, then B and then C, and
-the post-action code reference will executed first for C, then B and
+the post-action code reference will be executed first for C, then B and
 then finally A.
 
 Well behaved code should ensure that when setting up a