可以的，形容词作表语最常见，
其它词类，比如副词、名词、介词短语、动名词和动词不定式以及从句都是可以作表语的
It is here。here是副词
he is a worker 。worker是名词
He is at home 。at home 是介词词组
His job is looking after the baby。looking after是动名词
What he wants is to get the first prize。动词不定式作表语。
ps：哪类词作表语，关键在于它是否在系动词（常见的有be、feel、keep等）后面。
追问It is here。here是名词
追答您好，here是副词，