定语从句怎样判断关系代词是做主语还是宾语Heistheman.Hecameherelastweek.HeisthemanwhocameherelastweekSheisthewoman.Iservedheryesterday.SheisthewomanIservedyesterday.Theyarethebooks.Iboughtthebooks

　　定语从句怎样判断关系代词是做主语还是宾语

　　Heistheman.

　　Hecameherelastweek.

　　Heisthemanwhocameherelastweek

　　Sheisthewoman.

　　Iservedheryesterday.

　　SheisthewomanIservedyesterday.

　　Theyarethebooks.

　　Iboughtthebookslastyear.

　　TheyarethebooksIboughtlastyear

　　这里的关系代词who是做主语还是宾语是怎样判断的,求解