So mistype? Bad cut and paste?
No. The forum software interpreted the sequence of characters '[', 'i', and ']' in the "code" as the flag to start italicizing the text. Using code tags (by pressing the # icon) would have prevented that.
But nothing appears on the serial monitor! Help!!
It would appear, then, that you do not have the ADC connected correctly, or that you are using the wrong address to talk to it.