This is he speaking.

我就是。

You must have the wrong number.

你一定打错电话了。

I'll give him your message as soon as he's available.

他一有空我就转告他您的留言。

Seven o'clock, I'll pick you up at your office.

晚7点，我去办公室接你。

I just want to confirm that the arrangements have been made.

我要确认所有计划都安排好了。

Will you help me?

可以帮助我吗？