I find that English is too difficult for me.
我觉得英文太难了。

Don't let that get you down. You will get the hang of it.
不要因此而沮丧。你会掌握到窍门的。

I had tried many times and many ways, but I just can't speak a single word.
我试了很多次，试了很多种方法，但是我就是讲不出一个词。

Don't give up. You pick it up as you go.
别放弃。只要你坚持你能掌握的。

I'm not sure.
我不敢肯定。

Show some courage! I bet you can make it.
拿出点勇气来！我相信你可以的。