还是(Háishì, ”or” in the alternative question)
或者(Huòzhě, ”or” in the declarative Sentence)
The Difference Between 还是（Háishì） and 或者（Huòzhě）
Both 还是 (háishì) and 或者 (huòzhě) mean “or” and are used to present a choice. The usages of these two Chinese grammar conjunctions often confuse beginners while taking Chinese lesson. However, 还是 can only be used when asking a question and 或者 can only be used in a declarative sentence.
还是 is used to offer choices in a question
Subject + Verb + Option A + 还是 + Option B
1、你喝茶还是喝咖啡?( Nǐ hē chá háishì hē kāfēi? Would you like tea or coffee?)
2、你想去北京还是去上海？(Xiǎng qù běijīng háishì shànghǎi? Do you want to go to Beijing or Shanghai?)
还是 is used for questions that are embedded in sentences
Deciding whether or not to use 还是 becomes difficult with sentences that contain statements like “I don’t know,” “I want to know,” “I’m not sure,” etc. Alone, these statements are not technically questions. However, when used in a sentence that contains choices, these statements imply that a question must be answered. Therefore, you must use 还是.
1、他们还没决定要去北京还是上海。（Tāmen hái méi juédìng yào qù běijīng háishì shànghǎi. They have not decided yet whether they will go to Beijing or Shanghai.）
2、我不知道是接受还是不接受。（Wǒ bù zhīdào shì jiēshòu háishì bù jiēshòu I don’t know whether to accept or not.）
还是 is used to give suggestions
还是 can also be used to express the English words “ought to” or “had better”. The use of 还是 implies that the there were originally two options and the speaker has decided on one. In this grammar structure, 还是 often comes before the verb and sometimes before the subject. 吧 is often placed at the end of the statement to emphasize that it is a suggestion.
我听说这部电影不好看，我们还是看其他的吧。（Wǒ tīng shuō zhè bù diànyǐng bù hǎokàn, wǒmen háishì kàn qítā de ba.I heard this movie wasn’t good. We should watch another one.）
今天的作业特别难，我们还是问老师吧。（Jīntiān de zuòyè tèbié nán, wǒmen háishì wèn lǎoshī ba. Today’s homework is very hard. We had better ask the teacher.）
或者 is used to give options in declarative sentences
Option 1 + 或者 + Option 2
明天或者后天，我要和我的朋友见面。（Míngtiān huòzhě hòutiān, wǒ yào hé wǒ de péngyǒu jiànmiàn. I will meet my friends Either tomorrow or the day after.）