diff --git a/build/aclocal/gtk-3.0.m4 b/build/aclocal/gtk-3.0.m4
index f3b1402d77..8468ef17d6 100644
--- a/build/aclocal/gtk-3.0.m4
+++ b/build/aclocal/gtk-3.0.m4
@@ -182,7 +182,7 @@ main ()
           echo "*** If you have an old version installed, it is best to remove it, although"
           echo "*** you may also be able to get things to work by modifying LD_LIBRARY_PATH" ],
         [ echo "*** The test program failed to compile or link. See the file config.log for the"
-          echo "*** exact error that occured. This usually means GTK+ is incorrectly installed."])
+          echo "*** exact error that occurred. This usually means GTK+ is incorrectly installed."])
           CFLAGS="$ac_save_CFLAGS"
           LIBS="$ac_save_LIBS"
        fi
diff --git a/include/wx/richtext/richtextctrl.h b/include/wx/richtext/richtextctrl.h
index 229e6576c1..2327fe3dcc 100644
--- a/include/wx/richtext/richtextctrl.h
+++ b/include/wx/richtext/richtextctrl.h
@@ -2551,7 +2551,7 @@ public:
         { }
 
     /**
-        Returns the buffer position at which the event occured.
+        Returns the buffer position at which the event occurred.
     */
     long GetPosition() const { return m_position; }
 
diff --git a/src/propgrid/propgridpagestate.cpp b/src/propgrid/propgridpagestate.cpp
index a47af453fd..be435c4462 100644
--- a/src/propgrid/propgridpagestate.cpp
+++ b/src/propgrid/propgridpagestate.cpp
@@ -2123,7 +2123,7 @@ void wxPropertyGridPageState::DoDelete( wxPGProperty* item, bool doDelete )
             pg->m_deletedProperties.RemoveAt(index);
         }
         wxASSERT_MSG( pg->m_deletedProperties.Index(item) == wxNOT_FOUND,
-                    wxT("Too many occurences of the item"));
+                    wxT("Too many occurrences of the item"));
 
         index = pg->m_removedProperties.Index(item);
         if ( index != wxNOT_FOUND )
@@ -2131,7 +2131,7 @@ void wxPropertyGridPageState::DoDelete( wxPGProperty* item, bool doDelete )
             pg->m_removedProperties.RemoveAt(index);
         }
         wxASSERT_MSG( pg->m_removedProperties.Index(item) == wxNOT_FOUND,
-                    wxT("Too many occurences of the item"));
+                    wxT("Too many occurrences of the item"));
 
         delete item;
     }
@@ -2144,7 +2144,7 @@ void wxPropertyGridPageState::DoDelete( wxPGProperty* item, bool doDelete )
             pg->m_removedProperties.RemoveAt(index);
         }
         wxASSERT_MSG( pg->m_removedProperties.Index(item) == wxNOT_FOUND,
-                    wxT("Too many occurences of the item"));
+                    wxT("Too many occurrences of the item"));
 
         item->OnDetached(this, pg);
     }
diff --git a/src/x11/app.cpp b/src/x11/app.cpp
index 827c1cb80b..377c9582eb 100644
--- a/src/x11/app.cpp
+++ b/src/x11/app.cpp
@@ -508,7 +508,7 @@ bool wxApp::ProcessXEvent(WXEvent* _event)
         }
         case SelectionRequest:
         {
-            // A request to paste has occured.
+            // A request to paste has occurred.
             wxClipboardHandleSelectionRequest(*event);
             // The event handle doesn't care the clipboard
             // how to response requestor, so just return true.