He plants a tree.他种了一棵树.
He is planting a tree.他正在种树.
He has planted a tree.他已经种了一棵树.通常不会和一个明显的表示过去的时间一起用
He planted a tree(yesterday).他(昨天)种了一棵树.表示过去某个时间干了一件事
He has been planting a tree.他一直在种树.
He had planted a tree.他种过树.表示过去的过去干过某事
He had been planting a tree.他过去一直在种树.表示过去的过去一直在做某事
别的不知道了.时态有16种那么多吗?..