rain stay study 的现在进行时一般过去时怎么加

rainingIt's raining hard.雨下得很大.rainedIt rained hard,so I was late.因为大雨所以我迟到了.stayingI am just sitting and staying.我只能坐着不动.stayedThey stayed friends for years.他们的友谊维持了多年...