Question

be about to do sth be going to do sth will do sth

will do sth, be about to do sth, be to do sth, be going to do sth 和be doing 的区别
will do sth, be about to do sth, be to do sth, be going to do sth 和be doing 的详细用法及它们之间的区别

Answer 1

will do sth用在将来时态
be about to do sth 表示即将要干.不可以用在被动语态中
be to do sth有点按计划发生的意思,而且这个将来距现在不会太远.
例：They are to meet at the gate of the school.
他们将在学校门口见面.
The boy is to go to school tomorrow.
这个男孩明天将去上学.
be going to do sth 和will do sth 差不多,都是表示将来的事情,但will表示主观的
be doing sth用在进行时中,表示将来要发生的事情,并且事情是已经计划好的