Ni hao ma?
This simple phrase shows quite a bit about the Chinese grammar and structure that makes it so different from Latin based languages like English.
Literally translated, this phrase is "you good [question reflective]". The simplicity of the structure is a characteristic throughout the Chinese language. There isn't a formal verb as you would see in English, nor does there need to be. Chinese is a language of simplicity and flexibility as there is no need for a verb in order to understand the message here. You can try to stick the "to be" Chinese shi into the sentence but you'd be grammatically incorrect to a Chinese speaker.
The last part of the question, ma, doesn't literally have a translation in English. This is a reflective to help identify that this sentence should have an answer, it is a question.
In English, in order to ask a question, the last word of the sentence in inflected. Ones voice raises at the end to indicate a question that must be answered. To illustrate, say the following sentences aloud and notice how at the end of the sentence, your tone rises:
I know you. -- implying the directive
I know you? -- implying the question
In Chinese, to raise the tone on any given character would change its meaning. Inflections and tones are very important to pronunciation in the Chinese language. One common phrase given is "ma(flat) ma(rising) ma(fall-rise) ma(falling)". With the same sound but different inflections, one has just said "mother buy horse scold". Thus, there needs to be some sort of other way to distinguish a change in delivery of the phrase so that it becomes a question. This is where the ma comes in above. There are several of these expressive terms throughout the Chinese language that have no direct translation in English.
Interestingly enough, while this may be the most common phrase taught in Chinese, it's not actually used a lot by native speakers. Many these days shorten it even further to simply "Ni hao" to say "Hello". Even more modern to say "hello" is the term "Wei". If you trace back in history, greetings were more formally about food. It would not be uncommon to hear someone asking "Have you eaten yet?". Also, references to the day "Jian tian hao." would not be uncommon as a form of greeting rather than "how are you?"
Still, Ni hao ma? teaches several important aspects of this language and is a powerful phrase when first learning Chinese and a great way to start on your journey through this language.