Question

i don't know whether you happened to have heard or i don't know whether you happened to hear?

上面的两种说法那一个正确？

Answer 1

第一种正确，第一种强调听到的结果，我不知道你是否碰巧听说了。。。这个模誉“了迅码培”字是通过have heard来亩唯体现的

Answer 2

happen to hear 碰余启巧听说，固定搭配
我觉得用第二种
如果有时态塌悉变化也应该在happen而不是竖衫如hear上面~

Answer 3

B happend to do something,碰巧做某事