Keywords: on, at, about, concerning
Sign Definition
As a Verb or Adjective
                                            1.  To be located on a surface. English = (be) on.
                                          
                                          
                                        
                                            2.  To put something on a surface; to lay something on a surface; to place something on a surface.
                                          
                                          
                                        
                                            3.  To be located or situated at a place. English = (be) at.
                                          
                                          
                                        As Modifier
                                            1.  Used to re-introduce a topic of discussion. English = about, with reference to.
                                          
                                          
                                        
                                            2.  Used after many verbs (especially 'talk', 'write' and 'think') and before a noun to mean that the topic of the activity is the following noun. English = on, about, concerning, pertaining to.
                                          
                                          
                                         
                  
                      