1.whether...or not (表示选择或怀疑)是否,是不是
They now have two weeks to decide whether or not to buy...
现在他们有两周时间决定到底买还是不买.
2.whether...or ...不管,无论如何
This happens whether the children are in two-parent or one-parent families...
不管孩子是生活在双亲还是单亲家庭,这种情况都会发生.
3.whether +从句
Ask him whether he can come.
问他能不能来.