Make fields translatable (#14786)

diff --git a/erpnext/controllers/buying_controller.py b/erpnext/controllers/buying_controller.py
index f74c3a5..a22a9ec 100644
--- a/erpnext/controllers/buying_controller.py
+++ b/erpnext/controllers/buying_controller.py
@@ -737,8 +737,8 @@
 		""".format(item_list, fieldname), as_list=True)]
 
 	if invalid_items:
-		frappe.throw(_("Following item {items} {verb} not marked as {message} item.\
+		frappe.throw(_("Following item {items} {verb} marked as {message} item.\
 			You can enable them as {message} item from its Item master".format(
 				items = ", ".join([d for d in invalid_items]),
-				verb = "are" if len(invalid_items) > 1 else "is",
+				verb = _("are not") if len(invalid_items) > 1 else _("is not"),
 				message = message)))