做某人的笔友英语怎么说

The English expression for "being someone's pen pal" is "being a pen pal to someone". This phrase comes from the practice of exchanging letters with someone who lives in a different place, often through snail mail. This was a common way for people to communicate with each other before the widespread use of email and other forms of electronic communication.
Here are some examples of this phrase in use:
I've been a pen pal to Lisa for over 10 years. We started writing to each other when we were in high school.
My grandma used to have a lot of pen pals from different countries. She loved learning about different cultures and making friends all over the world.
I'm looking for someone to be a pen pal to. Do you want to exchange letters with me?
In Chinese, "being a pen pal to someone" can be translated as "做某人的笔友". Some examples of this phrase in use are:
我和丽莎做笔友已经有10多年了。我们在高中时就开始互写信了。
我奶奶以前有很多笔友，来自不同的国家。她喜欢了解不同的文化并在世界各地交朋友。
我正在寻找一个笔友。你想和我互写信吗？