Simplify the following text for a Grade 3 native English-speaking person.
Original: His eldest son , George W. Bush , was inaugurated as the 43rd President of the United States on January 20 , 2001 . Through previous administrations , the elder Bush had ubiquitously been known as `` George Bush '' or `` President Bush '' , but following his son 's election the need to distinguish between them has made retronymic forms such as `` George H. W. Bush '' and `` George Bush senior '' â '' and colloquialisms such as `` Bush 41 '' and `` Bush the Elder '' much more common .
Simplified: Because he has the same first and last names as his son , he is often called George H. W. Bush or George Bush Sr. ( George Bush senior ) .