情态动词是英语中的一类特殊动词，包括 can、could、may、might、shall、should、will、would、must 等。它们用于表达说话者对某种情态的看法、态度或推测。
那么，情态动词有没有过去分词呢？答案是：部分情态动词可以有过去分词形式。
具体来说，can、may、shall、will 这四个情态动词的过去分词形式分别是 could、might、should、would。例如，我们可以说：
- I could have gone to the party last night, but I was too tired.
- She might have missed the train.
- He should have studied harder for the exam.
- They would have won the game if they had played better.
但是，must 和 ought to 是两个例外。它们没有过去分词形式，只能用 have + 过去分词的结构来表达过去的推测或猜测。例如：
- He must have been very happy to see you.
- You ought to have told me earlier.
总之，情态动词虽然不像一般动词那样有一整套的时态变化形式，但它们的过去分词形式仍然是需要掌握的一部分，能够帮助我们更加准确地表达过去的看法和推测。
