过去将来时由“助动词should(第一人称)或would(第二、三人称)+动词原形”构成。在美国英语中,过去将来时的助动词一律用“would +动词原形”
过去将来时常由于宾语从句中,时间状语有:later, soon, the next (day)
在时间状语从句和条件状语从句中不可以使用过去将来时,而应该使用一般过去时
He promised that he would pay me a lot if I helped him with the project.(他答应付给我许多钱如果我帮助他搞那个项目)
表示纯粹的将来时用would或should,表示打算或主观认为的事情用was/were going to (+动词原形)
She told me she would be 18 the next month.(她告诉我她下个月就18岁了)
过去将来时还可以表示一个过去经常性的动作
When it rained in the day, he would bring an umbrella with him.(白天下雨时他会随身带一把雨伞)