Question

分析句子However,three days later a letter arrived,summoning me t

Answer 1

Ving做后置定语,是定语从句的缩略,先行词和动词是（主动）关系.

Three days later, a letter arrived, which summoned me to.

信召唤我去面试,是主动的,把关系代词和谓语去掉,变成Ving. Eg:

I have a friend, who sells shoes.

I have a friend, selling shoes.

如果是被动关系,则去掉.Eg:

I have a friend who is called Xiao Li.

I have a friend called Xiao Li.