这个字很难唸。

Zhège zì hěn nán niàn.

This word is difficult to pronounce.

这道题很难做。

Zhè dào tí hěn nán zuò.

This problem is very difficult to do.

学中文对我来说挺难的。

Xué Zhōngwén duì wǒ láishuō tǐng nán de.

Studying Chinese is quite difficult for me.