Chat box:
The chat box menu, located in the lower left hand corner of the screen has many uses, generally for communication, buy and sell and information. But in the Chat box menu, there are different commands needed in order to chat.

Typing or pressing the following will give you different areas of communication:

for "general chat mode" press alt + s (color of font is white)
example:
[General]kathy16 : hello!

for "party chat mode" press alt + p (color of font is green)
example:
[Party]kathy16 : hello!

for "all chat mode" press alt + a (color of font is white bluish)
example:
[All]kathy16 : hello!

for "guild chat mode" press alt + g (color of font is cyan)
example:
[General]kathy16 : hello!

for "alliance chat mode" press alt + l (color of font is violet/purple)
example:
[Alliance]kathy16 : hello!

to whisper with a player type at the chat box, the underscore (_) is a space, (color of font is light pink):
/w_(name of player)_(message)
example:
/w kathy16 hello!
output:
[Whisper]kathy16: hello