I was learning in a Mandarin class and I was kind of stumped on the use of "本来" and "原来" when filling in the blanks in a sentence. Here's my attempt to these questions (taken from 汉语口语速成: 基础篇 pp. 91-92):
- 这儿____是个冰场，现在盖起了高楼。(My answer was "原来", the answer is can be both.)
- 回国的日子____定在下月二十号，可是因为没有买到机票，就改到二十七号了。(My answer was "本来", the answer is "本来".)
- 这盘虾炒得太咸了，虾_____的味道都没有了。(My answer was "本来", the answer is "原来")
- 我找了你半天，____你在这儿呀。(My answer was "原来", the answer is can be both.)
There's no problem with the sentence #2 and #3. I got it right on the second sentence. I got it wrong on the third sentence, since I just know that "原来" can be used as an adjective, and the speaker already realized that the taste of the food is not good, hence my mistake.
What makes me confused is the answer of #1 and #4, is it true that either "本来" or "原来" correct in sentence #1 and #4? I thought only one of them can fit.
From what I understand from Chinese Grammar Wiki and some Chinese movies, my thinking is this:
I'm using “本来” when something unexpectedly happened, and the speaker doesn't realize until it happens. But if the speaker accidentally find out or realize the situation has changed, I should use “原来”.
Is my thinking true? If not, then on which case should I use "本来" or "原来"?
UPDATE: Here's another example I got from a movie:
The speaker use "本来" here, can it be changed to "原来"?