Task: Sentence Expansion
Input (English): The 1950s was the decade that started on January 1 , 1950 , and ended on December 31 , 1959 .
Output (English): The 1950s ( pronounced " nineteen-fifties " ; commonly abbreviated as the fifties ( among other variants ) ) was a decade of the Gregorian calendar that began on January 1 , 1950 , and ended on December 31 , 1959 .