"是否"在英語中怎么表示?

whether it is ture?\
這是否是真的呢？

whether ... or not

可以用whether或者if. 但是if只用在及物動詞后的賓語從句中。如：I don't know if/whether you are right.不可以用在名詞性從句中（主語從句，表語從句，同位語從句），以及介詞后面。
whether用法比較廣泛。后面可以加or not, 或者 to do sth.如
Whether or not he is right is unknown.
whether he is right or not is unknown.
I want to know whether to go out or not.

If ..(不加or not)
\比如:I dont know If you like him
whether ...or not(要加or not)
I dont know whether you like him or not

whether.../If ..