If someone calls, ask him to leave a message.

如果有人来电话，叫他留个口信。

youdao

If someone calls, tell them quietly that you will call them back soon.

如果有人打电话给你，你要小声地告诉他：你会马上打回去的。

youdao

I wonder what the bosses in China will say if someone calls in for a dog day off.

我倒想知道如果在咱们中国有人打电话请爱犬假，老板们会怎么回答。

youdao

So if someone calls you up and suggests that you might like to invest a bit in physical quantities of rare earth metals.

FORBES: Investing in Rare Earth Metals: Don't Do It!

If someone calls you on your mobile number while you're on a Skype call, you can now put the Skype call on hold and switch between the calls.

ENGADGET: Skype for Windows Phone 8 official preview available now (video)

What if someone calls him while he's on holiday?

CNN: Change Is in the Air