本来 and 原来 can be used as adverbs and indicate the former situation. In this case, these two words are interchangeable.
e.g.
我本来/原来在这家公司工作,现在不在了。(Wǒ běnlái/yuánlái zài zhè jiā gōngsī gōngzuò, xiànzài búzài le.) I used to work in this company, but I am no longer there.
我们本来/原来想去海南旅游,可是后来取消了。(Wǒmen běnlái/yuánlái xiǎng qù Hǎinán lǚyóu, kěshì hòulái qǔxiāo le.) We originally wanted to travel to Hainan, but we cancelled it later.
弟弟本来/原来学习西班牙语和汉语,但是现在只学汉语了。 (Dìdi běnlái/yuánlái xuéxí Xībānyá yǔ hé Hànyǔ, dànshì xiànzài zhǐ xué Hànyǔ le.) My younger brother used to learn Spanish and Chinese, but now he only learns Chinese.
Differences
1. 本来 needs to consider the later change, while 原来 has no such requirement when it’s used.
e.g.
我原来在这家公司工作。(Wǒ yuánlái zài zhè jiā gōngsī gōngzuò) I used to work in this company.
我本来在这家公司工作,现在不在了。(Wǒ běnlái zài zhè jiā gōngsī gōngzuò, xiànzài búzài le.) I used to work in this company, but I am no longer there.
我们原来想去海南旅游。(Wǒmen yuánlái xiǎng qù Hǎinán lǚyóu.) We originally wanted to travel to Hainan.
我们本来想去海南旅游,可是后来取消了。(Wǒmen běnlái xiǎng qù Hǎinán lǚyóu, kěshì hòulái qǔxiāo le.) We originally wanted to travel to Hainan, but we cancelled it later.
弟弟原来学习西班牙语和汉语。(Dìdi yuánlái xuéxí Xībānyá yǔ hé Hànyǔ.) My younger brother used to learn Spanish and Chinese.
弟弟本来学习西班牙语和汉语,但是现在只学汉语了。(Dìdi běnlái xuéxí Xībānyá yǔ hé Hànyǔ, dànshì xiànzài zhǐ xué Hànyǔ le.) My younger brother used to learn Spanish and Chinese, but now he only learns Chinese.
2. When being used as adjectives,
本来 means original, which can only modify nouns.
e.g.
这张照片就是这个学校的本来面貌。(Zhè zhāng zhàopiàn jiùshì zhège xuéxiào de běnlái miànmào.) This photo is the original face of this school.
这件衣服本来的颜色是很鲜艳的。(Zhè jiàn yīfú běnlái de yánsè shì hěn xiānyàn de.) The original colour of this dress is very bright.
原来 means former or previous, which indicates no change. It can’t be used as a predicate independently. And when modifying nouns, there must be used as 原来的.
e.g.
这只狗原来的名字叫贝贝。(Zhè zhǐ gǒu yuánlái de míngzì jiào Bèibei.) The original name of this dog was Beibei.
我还住在原来的地方,没有搬家。(Wǒ hái zhù zài yuánlái dì dìfāng, méiyǒu bānjiā.) I still live in the original place and haven’t moved.
这个地址是原来的,我已经不住在这儿了。(Zhège dìzhǐ shì yuánlái de, wǒ yǐjīng bù zhù zài zhèr le.) This address is the original one, and I don’t live here anymore.
Note that 原来 and 本来 can both modify abstract nouns, but for concrete nouns, only 原来 could apply.
Only 本来 can be used in the following situations:
1. 本来 means things are supposed to be so. The model verb such as 应该、要、得、会 and etc. is often used with it.
e.g.
我本来就会游泳。(Wǒ běnlái jiù huì yóuyǒng.) I could swim.
你们本来应该下个月去北京。(Nǐmen běnlái yīnggāi xià gè yuè qù Běijīng.) You should have gone to Beijing next month.
生活本来就是不容易的。(Shēnghuó běnlái jiùshì bù róngyì de.) Life is not easy.
2. The structure “本来+就……” is often used to refer to a development (compared with the previous situation). The structures like “又……” or “更……” often follow it to indicate progression.
e.g.
他本来就不会做饭,你们又不鼓励他,现在就更不喜欢做饭了。(Tā běnlái jiù bù huì zuò fàn, nǐmen yòu bù gǔlì tā, xiànzài jiù gèng bù xǐhuān zuò fànle.) He didn’t know how to cook, and you didn’t encourage him. Now he doesn’t like cooking even more.
我本来就不想去上学,而且又下雪了,就更不想去了。(Wǒ běnlái jiù bùxiǎng qù shàngxué, érqiě yòu xià xuěle, jiù gèng bùxiǎng qùle.) I didn’t want to go to school, and it’s snowing again, so I don’t want to go anymore.
这个人本来就穷,又不想工作,就更没钱了。(Zhège rén běnlái jiù qióng, yòu bùxiǎng gōngzuò, jiù gèng méi qián le.) This person is already poor and doesn’t want to work, so he has no money.
Only 原来 can be used in the following situations:
原来 indicates a sudden realization or understanding of something unknown before.
e.g.
我以为你是中国人,原来你是学中文的学生。你的汉语真好!(Wǒ yǐwéi nǐ shì zhōngguó rén, yuánlái nǐ shì xué zhōngwén de xuéshēng. Nǐ de hànyǔ zhēn hǎo!) I thought you were Chinese, but you are a student of Chinese. Your Chinese is really good!
原来是你啊!二十年没见,我都快不认识你了。(Yuánlái shì nǐ a! Èrshí nián méi jiàn, wǒ dū kuài bù rènshí nǐle.) So, it’s you! I haven’t seen you in twenty years, I almost can’t recognize you anymore.
这个字原来是这么写的啊!(Zhège zì yuánlái shì zhème xiě de a!) That’s how the word was originally written!
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