请帮我看看这句话的时态,
at that moment i was having lunch with my guest.这句话我不知道为什么不能写成这样,at that moment i was have lunch with my guest.这有什么区别阿
这里的having是现在分词,还是动名词阿,
既然是进行时，应该是现在分词才对阿