be heard doing /do 有具体时间用doing?

be heard doing /do 有具体时间用doing? be heard to do be be heard to be doing be heard doing be heard to doing我知道前两个是对的,后两个存在吗?若存在四个进行比较,有何区别be heard to dobe heard to be doing be heard doing be heard to doing如果不存在，前两 有没有be heard doing? be heard to do sth 还是 be heard doing sth? 请问be heard to do/do/doing之间的区别以及是否存在be heard do 的说法 saw、heard sb______(do/doing) sth be going to,be doing,will do有什么区别 be doing与be going to do有什么区别? be to do.be going to do.be doing.will do.有什么区别? will do 和 will be doing有什么区别? I heard you came across some Americans last Sunday其中的came用过去式?(我知道后面有last Sunday) 但heard不是跟do 或doing? heard +doing和do的区别使用错了，hear used to do, be used to doing , be used to do 有什么区别? 有没有be fun with,be fun to do和be fun doing这些说法? be used to doing,be used to do,used to do,be used for,be used by有什么区别. 有没有be bored doing,be bored to do,be bored in doing,be bored in to do?请问有没有这些说法 be prepare do 还是be prepare doing be sure to do和be sure of doing 的区别be sure to do和be sure of doing的意义有什么不同