"mi abuelo esta muerto" my grandpa is dead. En español uno esta muerto, no es muerto, unlike english.

Hi Dominic! Please check the Webseite sometimes grammatical rules are not pure mathematics: http://spanish.about.com/od/usingparticularverbs/a/muerto.htm They also ask themselves the same question why not: "Mi padre es muerto" Best!

It is "estar muerto". Many Spanish teachers will state that "estar" is used to describe temporary conditions whereas "ser" is used to discuss permanence. However, this is not entirely accurate as illustrated in this example. In the case of "estar muerto", we are contrasting two states of being. In this case you are either "muerto" or "vivo". This is why we use "estar" here.

Mi abuelo es un hombre muy sabio (what kind of man he is) very clever or wise Mi abuelo era un hombre muy sabio ( what kind of man he was) Mi abuelo está vivo/ muerto ( his state/condition) he is alive/dead

Hi, Dominic! The correct form to say that is "Mi abuelo está muerto". Espero haberte ayudado. If you have anyother question, dont hesitate to contact me. ¡Saludos!