我来这里是来见约翰。

I'm here to see John.

For example:

A: May I help you?我能帮助您吗？

B: I'm here to see John. 我来这里是来见约翰。

请随便坐。

Please make yourself comfortable.

For example:

A: Please make yourself comfortable.请随便坐。

B: Thank you.谢谢你。

你要咖啡吗？

Can I get you some coffee?

For example:

A: Can I get you some coffee?你要咖啡吗？

B: No, thank you.不要，谢谢。

恐怕托马斯小姐现在不能见你。

I'm afraid Ms. Thomas is unable to meet with you now.

For example:

A: I'm afraid Ms. Thomas is unable to meet with you now.

恐怕托马斯小姐现在不能见你。

B: May I schedule an appointment?我可以安排个时间吗？

be unable to do 不能做......

我可以进去见林先生吗？

Can I go in to see Mr. Lin?