A simple yes/no question can be formed by adding 吗 add the end of the sentence.
Compare 你是学生 nǐ shì xuésheng You are a student v. 你是学生吗? Nǐ shì xuésheng ma? Are you a student?.
什么 shénme what can be used either as a modifier as in 什么名字 shénme míngzì what name or as a pronoun:
你的专业是什么? Nǐ de zhuānyè shì shénme? What do you study? or literally Your specialty is what?
哪 nǎ also meaning what is only used as a modifier. 你是哪国人 Nǐ shì nǎ guórén? Literally, You are what country person?.
Note that the word order does not change. The question word appears in the same position as would the corresponding answer in a declarative sentence.
你的专业是什么? - 我的专业是中文。
Nǐ de zhuānyè shì shénme? - Wǒ de zhuānyè shì Zhōngwén.
Literally, Your speciality is what? - My speciality is Chinese.
你是哪国人? - 我是英国人。
Nǐ shì nǎ guórén? - Wǒ shì Yīngguórén
Literally, You are what country person? - I am England person.
呢 ne is a question particle used to ask if a previous statement applies to the current situation too.
For example: When somebody states 我很好 Wǒ hěn hǎo I am very well, they may then continue with 你呢 Nǐ ne And you meaning are you well too, how about you.