But you'll never know unless you try.

但如果不试你永远不知道。

youdao

Sophia: But you'll never know if you don't make the effort.

苏菲雅：你不努力看看，你就永远不会知道。

youdao

Then you'll learn not only the language in context but all the words you really need to know (but somehow never learned in Portuguese 102).

这样，你就不仅仅能够学习到语言的前后关系，而且还能学习到你需要了解的所有词汇。 （但是由于某种原因从没学过葡萄牙语102）（ 译者注：括号里的原文是：but somehow never learned in Portuguese 102。

youdao

But you'll never know, will you?

ENGADGET: MIT project uses cellphone data to predict activities

So I doubt if we'll do it, but you never know.

FORBES: Yar! Disney Banks On Box Office Booty

We wouldn't hesitate to offer our recommendations of investing in a second BD deck -- after all, you never know when you'll need one for travel or loan -- but there's a whole heap to choose from in the entry-level sector.

ENGADGET: Ask Engadget HD: A second Blu-ray deck, or an upscaling DVD player?