写一封信用英语怎么说短语

"Write a letter" in English can be expressed as "compose a letter".
This phrase is derived from the verb "compose", which means to create or put together something, usually in writing.
Examples of this phrase in use:
"Could you please compose a letter to our clients explaining the changes to our services?"
"I need to compose a letter to my friend to update them on my life."
Translations:
"请您写一封信给我们的客户，解释我们服务的变化?"
"我需要给我的朋友写一封信，告诉他们我生活的最新情况。"