Hi,

Ni3 Hao3! should be NI2 HAO3! This is a rule in Chinese. for most two characters' vocabularies, if the two characters are both in the third tone, the first character should change to the second tone. ni 2 hao3 is an example of this. another example is ma2 yi3( ant),but, if you see the two character separately, they are in their original tone, ni3, hao3 and ma3, yi3. There are also a few vocalbularies that we change the second character to the seond tone, for this group of vocabulaires, no rules , have to remember.