to是介词为什么be going to是情态动词

to是介词为什么be going to是情态动词 能是be going to be able be used to和used to的to是介词还是动词不定式?为什么? 为什么agree to 的to 是介词? be going to是啥意思啊. be going to是动名词吗 it seems as if it is going to rain中的be going to 可以换成will吗?为什么答案只能是选择be going to 关于 be going to 的用法例句：I am going to Australia.这个句子的谓语是什么?为什么?be going to 是情态动词吗? there （ ）a meeting tomorrow afternoon ​there （ ）a meeting tomorrow afternoonAwill be going to Bwill going to be C is going to be Dwill going to be答案是c为什么啊?我觉得a也行啊 be attractive to sb此中的to是介词吗 be used to 中的to 是介词还是不定式? be favorable to 的to是介词吗 be keen to的to是介词吗 be dying to中的to是介词吗 be crucial to里面的 to 是介词吗 be going to do going是动词加ing吗 be going to do里going是动词还是名词? be going to加介词短语时要省略to,为什么?是小学6年级英语课本中出现的句子：i am going by train.如果写成i am going to by train是不是就错了?我是这样想的,因为当提问地点的时候是：where are you going?