0N? H?o is the greeting 'hello' in Mandarin Chinese. This literally means 'You well'. However, when you greet someone formally or greet an elder person or someone you respect such as a teacher, you should say Nín h?o.N? and Nín are the pronoun 'you' without and with respect respectively.
This way of writing Chinese words using English is called the Pinyin system of Romanisation. The strange marks above the words are tone marks. Mandarin is a tonal language and every syllable has one of the 5 tones prevelant in the language.
