Is he going to have a picnic tomorrow?过去式(用last weekend)

过去式啊，did是助动词，was是系动词， did提问的是过去发生的动作，接的是动词，如 Did you go(动词原形) to school yesterday? was直接提问的是名词、形容词等，如： Was he happy yesterday? 当然，如果是过去进行时或者过去将来时会用was，如： Was he sleeping when you came back yeasterday? Was he going to sing if he felt happy? 你可以把句子还原成肯定句，was变成肯定句，也存在，did变成肯定句就不存在了，而是用动词的过去式代替。比如此题，变为肯定句是： He had a picnic last weekend. 而不是： He was have a picnic last weekend. 当然，如果说： He was going to have a picnic last weekend. 这种说法也可以，过去将来时。不过时间条件上应该更明显些!