This is the 323rd most frequent Chinese word.
原
"原" means "origin," "source," "cause," or "plain" (as in a flat expanse of land).
In this sentence, "原来" emphasizes a sudden realization or discovery about the situation.
原来是你帮我完成了这个任务。
So it was you who helped me complete this task.
Here, "原" describes the original location or state before the change.
我们计划从原地区搬迁到新的地方。
We plan to relocate from the original area to a new place.
In this sentence, "原由" refers to the underlying reason or cause for an action or event.