成人高考专升本英语动词不定式时态语态：

    动词不定式的时态和语态，动词不定式有三种时态(一般时、进行时和完成时)和两种语态(主动态和被动态)的变化。

    动词不定式的三种时态表现形式：一般时    to do
                                  进行时    to be doing
                                  完成时    to have done

    动词不定式的被动语态表现形式: to be done
    动词不定式的否定式的表现形式: not to do

    例：I couldn't ask him to come.
    我不能请他来。(一般时)

    He feels so good to be working with some friends at such a moment.
    他感觉在这样的时候与几个朋友一起工作真是太好了。(进行时)

    He seems to have read that letter.
    他似乎已经看过那封信了。(完成时)

    The book he wrote is going to be sent to the publisher.
    他写的书就要被寄到出版社了。(被动态)

    He decided not to quit the job.
    他决定不放弃这份工作。(否定式)