I had hoped to brush up my Spanish.

我曾希望提高一下我的西班牙语。

I must brush up on my Spanish before I go to Seville.

我去塞维利亚之前一定得好好温习我的西班牙语。

Tom needs to brush up on his English.

汤姆需要提高一下他的英语水平。

I really need to brush up on my math.

我真的需要认真复习一下数学。

I really need to brush up on my French.

我确实需要提高我的法语水平。