"本来 我打算...." 中的"本来"用哪个英语表达比较好？

一般用Originally，指 本来，原来等等，可以独立在句首。
但是能表示“本来，我打算……”这种意思的表达方式还很多，要看实际情况了，你可以参考下列的例句：

1. 这房子本来的主人是威灵顿公爵。
The original owner of the house was the Duke of Wellington.

2. 他本来不必买这样一所大房子。
He originally need not buy such big house.

3. 我本来希望来这里，但没能做到。
I had hoped to come here, but I couldn't.

4. 没问题，今天下午本来就不很忙。
Okay. It's not very busy this afternoon anyway.

5. 艾丽卡：我本来会给你整个世界。
Elektra King: I could have given you the world.

6. 丽塔：本来是，但是今天我破例。
Rita: I was, but I'm breaking it today.

planning to do +STH
这就可以表达你的意思了

应该是 mean to do sth

wanted to
intended to
was going to
这些都行，
还可以用had intended to ，看情况了

可以用副词 originally 表示本来
本来打算做 originally intend to do sth