4 sentences

1. 请问阁下尊姓大名？

   qǐng​wèn gé​xià zūn​xìng dà​míng?

   May I ask your distinguished name?

   Source: Dong Chinese Dictionary

2. 在下复姓欧阳，不知阁下如何称呼？

   zài xià fù​xìng ōu​yáng, bù zhī gé​xià rú​hé chēng​hu?

   My humble name is Ouyang; how may I address you?

   Source: Dong Chinese Dictionary

3. 阁下的见解确实高明，令我十分钦佩。

   gé​xià de jiàn​jiě què​shí gāo​míng, lìng wǒ shí​fēn qīn​pèi.

   Your Excellency's insights are indeed brilliant, and I admire them greatly.

   Source: Dong Chinese Dictionary

4. 总统阁下将于今日下午抵达北京进行国事访问。

   zǒng​tǒng gé​xià jiāng yú jīn​rì xià​wǔ dǐ​dá Běi​jīng jìn​xíng guó​shì fǎng​wèn.

   His Excellency the President will arrive in Beijing this afternoon for a state visit.

   Source: Dong Chinese Dictionary