关于情态动词的两道题

if you don't like to swim , you _____ stay at home .
A. should as well B. may as well C. can as well D. would as well
答案是B, may/might as well do sth 是固定搭配"还是.....好, 不放.....(做某事)"的意思.

He began to write two hours ago.He _______ have finished the article now .
A. must B. ought C. ought to D. had to
答案是C. 因为他说He began to write two hours ago.所以猜测他可能/应当已经finished the article now . 并不能确定他肯定是完成了那个文章的.所以不能用must,因为must是对事实非常确定的意思.

may的语气更委婉
must相当于肯定的意思，ought to 不确定的成分更多一些

if you don't like to swim , you _____ stay at home .
A. should as well B. may as well C. can as well D. would as well
答案是B, 但我觉得C也可以,那为什么不选C呢 ??
may as well 意思是"也可以",语气上比"can as well(也能)" 要委婉得多,用can as well语气上显得有些生硬.所以这里选B而不选C.

He began to write two hours ago.He _______ have finished the article now .
A. must B. ought C. ought to D. had to
答案是C, 但我觉得A也可以啊, 表示对事情的肯定的推测.那为什么不选A呢
ought to