这道题有点难，我得好好琢磨一下。

Zhè dào tí yǒudiǎn nán, wǒ děi hǎohǎo zuómo yíxià.

This problem is a bit difficult; I need to think it over carefully.

有空的时候，我总爱琢磨怎样提高自己的中文水平。

Yǒu kòng de shíhou, wǒ zǒng ài zhuómó zěnyàng tígāo zìjǐ de Zhōngwén shuǐpíng.

When I have free time, I always like to think about how to improve my Chinese level.

他琢磨了几天，终于想出一个更好的方案。

Tā zuómo le jǐ tiān, zhōngyú xiǎngchū yí gè gèng hǎo de fāng'àn.

He thought it over for several days and finally came up with a better plan.