王wáng先xiān生shēng，请qǐng进jìn。

Mr. Wang, please come in.

我wǒ先xiān生shēng今jīn天tiān出chū差chà了liǎo。

My husband is on a business trip today.

请qǐng问wèn您nín是shì李lǐ先xiān生shēng吗ma？

Excuse me, are you Mr. Li?

这zhè位wèi先xiān生shēng想xiǎng点diǎn菜cài。

This gentleman would like to order.

这zhè位wèi先xiān生shēng是shì我wǒ的de老lǎo师shī。

This gentleman is my teacher.