Title: HSK / HSK1 / HSK1-1.dictionary.en

Translated: you (informal, as opposed to courteous 您[nin2])
Pinyin: nǐ
Simplified: 你

Translated: good
Pinyin: hǎo
Simplified: 好

Translated: you (courteous, as opposed to informal 你[ni3])
Pinyin: nín
Simplified: 您

Translated: hello; hi
Pinyin: nǐ hǎo
Simplified: 你好

Translated: hello (polite)
Pinyin: nín hǎo
Simplified: 您好

Translated: I'm sorry; excuse me; I beg your pardon
Pinyin: duì bu qǐ
Simplified: 对不起
Traditional: 對不起

Translated: it doesn't matter
Pinyin: méi guān xi
Simplified: 没关系
Traditional: 沒關係