是表語從句,用在be動詞后面,這個從屬連接詞that只起連接作用,是無名英雄,在從句中不作任何成分,如：The problem is that I can't speak French.The problem is that I can't type Tibetan.但是在口語中把that常常省...there being nothing to do,we just talked on and on.獨立主格 我要換成was，這句話還對嗎？不考慮獨立主格，光說句子 there was nothing to do,we just talked on and on. 這樣對嗎？不對，逗號是不能分隔兩個獨立的句子的，肯定是一句主句，另一句是從句，或者兩句句子之間一定要加對等連接詞so，如：There was nothing to do, so we just talked on and on.如果不加對等連接詞，則一定用獨立主格，希望我能幫助你解疑釋惑。