whether与that的区别同时引导句子的时候whether和that有什么区别?learn的意思作“了解；获息”时,表结果吗?希望能说的全面写whether和that的意思我知道，关建是用法learn解释为“了解，获息”时，表结果，那比如说：I learn that/whether it is expensive.用whether还是用that正确？whether 与that 都能引导从句，不用别乱说哦

区别很大啊
whether是做是否讲的,而that后引导的只是一个句子,不作为"是否"讲

你的句子两个都对，一个是我了解到那东西很贵，一个是我知道了那个东西是否很贵

1.whether 是否
例:I don't know whether you really don't know it.
而that引导的句子最为广泛,但在该使用whether语句的时候不可以替换whether. whether: He seemed undecided whether to go or stay.他似乎还没决定好是走还是留下.

2.that 表引导．
例：I learned that ...
一般接在动词后面表宾语．
也可以表结果等等．She was so tired that she couldn't think deep.

that 否定
whether 肯定

1.whether 是否例:I don't know whether you really don't know it.前面一般是否定.而that引导的句子最为广泛,但在该使用whether语句的时候不可以替换whether.I doubt that you don't know the truth.2.learn作为"了...

应该是I learn that it is expensive.
whether: He seemed undecided whether to go or stay.他似乎还没决定好是走还是留下.
that: She was so tired that she couldnt think straight.她累得快不行了.
其实that是摆在一个句子中后半部分跟随的句子的前面...she couldnt think straight是一个句字来的...但是前面she was so tired 也是一个句子...