在改一般疑问句时,带头的第一个单词可以是Does吗?

当然可以，实义动词作谓语,只有主语是第三人称单数才用Does···
这句可以改成：Does Tom like singing?

可以,实义动词作谓语,主语是第三人称单数时,如
He goes to school on foot every day.->
Does he go to school on foot every day?

可以改成Does Tom like singing?