平信

Are you sending it by regular or by speed?

你要寄平信还是快递？

I don´t think there´s any need to send an express letter but to write more often. "

不必发快信，多写几封平信，倒是真的。 ”

Do you want to send it as an ordinary or registered letter.

您想寄平信还是挂号信？

Do you want to send it by air mail or surface mail?

你想寄航空信还是平信？

You can send the letter by airmail ( regular mail, registered mail ).

你可以邮寄航空信 （ 平信 、 挂号信 ）。