系动词常接词语类型例句：
is a student.(名词）
bag is mine.(代词）
is twelve this year.(数词）
man is old.（形容词）
!Jim is over there .(副词或副词短语）
father is at home today.(介词短语）
wish is to be an artist.(不定式或不定式短语）
favorite sport is swimming.(动名词或动名词短语）
problem is when we will start tomorrow.(表语从句）
