is the pinyin representation of two characters, 你, pronounced nǐ, personal pronoun meaning ‘you’ and 好, pronounced hǎo, meaning good. Note both of these characters are 3rd tone. So, to say hello in Mandarin Chinese, say Ni Hao (written 你好). Link to an audio example here.
When I was in China, a friend of mine from the UK was relocating to another country, and I asked him if he would miss living there, remarking, “Who will you say Nihao to 100 times a day?”. Anyone living in China would know right away what I meant, as this simple greeting meaning hello (literally “you good”) is said to everyone you meet, and on an average day that would be a lot of people. Most of the foreigners who visit China will be in an urban (or at least sub-urban) area where the population density is quite high. Interacting with scores of people, friends and strangers alike – all get the Nihao greeting.
Another factor that pads the amount ‘Nihao’ is uttered is the habit of speakers to repeat the greeting a couple of times in a slightly rapid sequence, as Mandarin speakers often use repetition in speech for rhythm and stress. These kind of language nuances are taught as part of the courses offered at The China Center, where we stress real communication in Mandarin. Contact us for more info.
The easy answer to that question is: “Because 20% of the world’s population speaks Chinese”.