我用的是推荐信。网上有很多模板。
To Whom It May Concern:
I am happy to write a letter of recommendation for *** regarding his ability
to speak and write in English. I know *** in two capacities. One, he rented
a room from me starting on *** when he first came from China. I was amazed
at that time at his proficiency in English. We had daily conversations about
different subjects, from simple interactions such as introductions and
greetings to more complex conversations relating to in depth analysis of a
variety