diff --git a/src/errors.h b/src/errors.h
index 82708d3..9a2c394 100644
--- a/src/errors.h
+++ b/src/errors.h
@@ -2761,9 +2761,9 @@
 #endif
 EXTERN char e_yank_register_changed_while_using_it[]
 	INIT(= N_("E1064: Yank register changed while using it"));
+EXTERN char e_command_cannot_be_shortened[]
+	INIT(= N_("E1065: Command cannot be shortened: %s"));
 #ifdef FEAT_EVAL
-EXTERN char e_must_use_var_instead_of_va[]
-	INIT(= N_("E1065: Must use :var instead of :va"));
 EXTERN char e_cannot_declare_a_register_str[]
 	INIT(= N_("E1066: Cannot declare a register: %s"));
 EXTERN char e_separator_mismatch_str[]
diff --git a/src/evalvars.c b/src/evalvars.c
index 56ac3da..44882ca 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -768,11 +768,6 @@
 	emsg(_(e_cannot_declare_variable_on_command_line));
 	return;
     }
-    if (eap->arg > eap->cmd && !has_var)
-    {
-	emsg(_(e_must_use_var_instead_of_va));
-	return;
-    }
     ex_let(eap);
 }
 
diff --git a/src/ex_cmds.h b/src/ex_cmds.h
index 3cdb656..40e5075 100644
--- a/src/ex_cmds.h
+++ b/src/ex_cmds.h
@@ -58,6 +58,7 @@
 #define EX_NONWHITE_OK 0x2000000  // command can be followed by non-white
 #define EX_KEEPSCRIPT  0x4000000  // keep sctx of where command was invoked
 #define EX_EXPR_ARG    0x8000000  // argument is an expression
+#define EX_WHOLE      0x10000000  // command name cannot be shortened in Vim9
 
 #define EX_FILES (EX_XFILE | EX_EXTRA)	// multiple extra files allowed
 #define EX_FILE1 (EX_FILES | EX_NOSPC)	// 1 file, defaults to current file
@@ -221,7 +222,7 @@
 	EX_BANG|EX_RANGE|EX_CMDARG|EX_TRLBAR,
 	ADDR_OTHER),
 EXCMD(CMD_break,	"break",	ex_break,
-	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_breakadd,	"breakadd",	ex_breakadd,
 	EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
@@ -281,7 +282,7 @@
 	EX_RANGE|EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_LINES),
 EXCMD(CMD_catch,	"catch",	ex_catch,
-	EX_EXTRA|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_cbuffer,	"cbuffer",	ex_cbuffer,
 	EX_BANG|EX_RANGE|EX_WORD1|EX_TRLBAR,
@@ -413,7 +414,7 @@
 	EX_NEEDARG|EX_EXTRA|EX_NOTRLCOM|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_const,	"const",	ex_let,
-	EX_EXTRA|EX_BANG|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_BANG|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_copen,	"copen",	ex_copen,
 	EX_RANGE|EX_COUNT|EX_TRLBAR,
@@ -548,16 +549,16 @@
 	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_else,		"else",		ex_else,
-	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_elseif,	"elseif",	ex_else,
-	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_emenu,	"emenu",	ex_emenu,
 	EX_NEEDARG|EX_EXTRA|EX_TRLBAR|EX_NOTRLCOM|EX_RANGE|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_OTHER),
 EXCMD(CMD_endif,	"endif",	ex_endif,
-	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_endinterface,	"endinterface",	ex_ni,
 	EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
@@ -575,13 +576,13 @@
 	EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_endfor,	"endfor",	ex_endwhile,
-	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_endtry,	"endtry",	ex_endtry,
-	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_endwhile,	"endwhile",	ex_endwhile,
-	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_enew,		"enew",		ex_edit,
 	EX_BANG|EX_TRLBAR,
@@ -623,10 +624,10 @@
 	EX_RANGE|EX_BANG|EX_FILE1|EX_CMDARG|EX_ARGOPT|EX_TRLBAR|EX_NEEDARG,
 	ADDR_OTHER),
 EXCMD(CMD_final,	"final",	ex_let,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_finally,	"finally",	ex_finally,
-	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_finish,	"finish",	ex_finish,
 	EX_TRLBAR|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
@@ -1601,7 +1602,7 @@
 	EX_RANGE|EX_BANG|EX_TRLBAR|EX_ZEROR,
 	ADDR_OTHER),
 EXCMD(CMD_throw,	"throw",	ex_throw,
-	EX_EXTRA|EX_NEEDARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NEEDARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_tjump,	"tjump",	ex_tag,
 	EX_BANG|EX_TRLBAR|EX_WORD1,
@@ -1694,7 +1695,7 @@
 	EX_RANGE|EX_WHOLEFOLD|EX_EXTRA|EX_DFLALL|EX_CMDWIN|EX_LOCK_OK|EX_NONWHITE_OK,
 	ADDR_LINES),
 EXCMD(CMD_var,		"var",		ex_var,
-	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_EXPR_ARG|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_version,	"version",	ex_version,
 	EX_EXTRA|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
@@ -1763,7 +1764,7 @@
 	EX_BANG|EX_TRLBAR|EX_CMDWIN|EX_LOCK_OK,
 	ADDR_NONE),
 EXCMD(CMD_while,	"while",	ex_while,
-	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK,
+	EX_EXTRA|EX_NOTRLCOM|EX_SBOXOK|EX_CMDWIN|EX_LOCK_OK|EX_WHOLE,
 	ADDR_NONE),
 EXCMD(CMD_winsize,	"winsize",	ex_winsize,
 	EX_EXTRA|EX_NEEDARG|EX_TRLBAR,
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 287045b..6b2bdd4 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3745,16 +3745,27 @@
 							    (size_t)len) == 0)
 	    {
 #ifdef FEAT_EVAL
-		if (full != NULL
-			   && cmdnames[(int)eap->cmdidx].cmd_name[len] == NUL)
+		if (full != NULL && cmdnames[eap->cmdidx].cmd_name[len] == NUL)
 		    *full = TRUE;
 #endif
 		break;
 	    }
 
-	// :Print and :mode are not supported in Vim9 script
-	if (vim9 && (eap->cmdidx == CMD_mode || eap->cmdidx == CMD_Print))
-	    eap->cmdidx = CMD_SIZE;
+	// :Print and :mode are not supported in Vim9 script.
+	// Some commands cannot be shortened in Vim9 script.
+	// ":continue" needs at least ":cont", since ":con" looks weird.
+	if (vim9 && eap->cmdidx != CMD_SIZE)
+	{
+	    if (eap->cmdidx == CMD_mode || eap->cmdidx == CMD_Print)
+		eap->cmdidx = CMD_SIZE;
+	    else if (((cmdnames[eap->cmdidx].cmd_argt & EX_WHOLE)
+			  && len < (int)STRLEN(cmdnames[eap->cmdidx].cmd_name))
+		      || (eap->cmdidx == CMD_continue && len < 4))
+	    {
+		semsg(_(e_command_cannot_be_shortened), eap->cmd);
+		eap->cmdidx = CMD_SIZE;
+	    }
+	}
 
 	// Do not recognize ":*" as the star command unless '*' is in
 	// 'cpoptions'.
@@ -3775,8 +3786,8 @@
 	    eap->cmdidx = CMD_SIZE;
     }
 
-    // ":fina" means ":finally" for backwards compatibility.
-    if (eap->cmdidx == CMD_final && p - eap->cmd == 4)
+    // ":fina" means ":finally" in legacy script, for backwards compatibility.
+    if (eap->cmdidx == CMD_final && p - eap->cmd == 4 && !vim9)
 	eap->cmdidx = CMD_finally;
 
 #ifdef FEAT_EVAL
diff --git a/src/testdir/test_vim9_script.vim b/src/testdir/test_vim9_script.vim
index f60fb36..a503d11 100644
--- a/src/testdir/test_vim9_script.vim
+++ b/src/testdir/test_vim9_script.vim
@@ -460,7 +460,7 @@
     endtry
   catch /wrong/
     add(l, 'caught')
-  fina
+  finally
     add(l, 'finally')
   endtry
   assert_equal(['1', 'caught', 'finally'], l)
@@ -1004,7 +1004,7 @@
 def s:ReturnFinally(): string
   try
     return 'intry'
-  finall
+  finally
     g:in_finally = 'finally'
   endtry
   return 'end'
@@ -3374,6 +3374,37 @@
   g:StopVimInTerminal(buf)
 enddef
 
+def Test_minimal_command_name_length()
+  var names = [
+       'cons',
+       'brea',
+       'cat',
+       'catc',
+       'con',
+       'el',
+       'els',
+       'elsei',
+       'endfo',
+       'en',
+       'end',
+       'endi',
+       'endw',
+       'endt',
+       'endtr',
+       'fina',
+       'finall',
+       'th',
+       'thr',
+       'thro',
+       'wh',
+       'whi',
+       'whil',
+      ]
+  for name in names
+    v9.CheckDefAndScriptFailure([name .. ' '], 'E1065:')
+  endfor
+enddef
+
 def Test_unset_any_variable()
   var lines =<< trim END
     var name: any
diff --git a/src/version.c b/src/version.c
index 999f8ac..3766c11 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4510,
+/**/
     4509,
 /**/
     4508,
diff --git a/src/vim9compile.c b/src/vim9compile.c
index 52c60fb..634f24e 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -1883,13 +1883,6 @@
     lhs_T	lhs;
     long	start_lnum = SOURCING_LNUM;
 
-    p = eap->cmd;
-    if (eap->cmdidx == CMD_var && arg > p && !checkforcmd_noparen(&p, "var", 3))
-    {
-	emsg(_(e_must_use_var_instead_of_va));
-	return NULL;
-    }
-
     // Skip over the "varname" or "[varname, varname]" to get to any "=".
     p = skip_var_list(arg, TRUE, &var_count, &semicolon, TRUE);
     if (p == NULL)