Question

英语句子结构分析的问题，麻烦大家帮我解答

I reckon William could have been telling the truth.
could have been telling 请问这是什么时态？是虚拟语气吗？
如果是虚拟语气，为什么不用could have told the truth？ 谢谢！

Answer 1

你好。
这不是虚拟语气，是表示对过去事情进行猜测的句子，结构是：情态动词 + 完成（进行）时。退回到原始句，结构是：it is possible that William was telling the truth.
如果是could have told the truth，原始句就是：
it is possible that William told the truth.
记住，知道了原始句，对后来的发展句就容易理解了。难道你们老师不在这方面启发你们？