The wind blows east to west because it is below 30 degrees north of the equator. (tropical easterlies)
Primarily from the southwest.
It's prevailing Winds
East to west on a normal year, and west to east on el niño years
Because of the Earth's Rotation...
you have to use some thing like a sock and point it out somewhere outside
wind does not "usually" blow in one direction it blows in all directions (direction depends on where you are) and wind has a random direction and speed do to the fact that win…d is created through air currents and the uneven heating of the earth by the sun so as cold air travels down and hot air travels up the air is pushed around in random directions which creates gusts of air (wind) and a steady breeze is created by air current (the air travels in one direction at a certain speed in different regions(areas). However there is a general wind direction that depends on latitude. Polar wind Tropical winds tend to travel to the west and toward the equator while mid-latitude winds tend to travel east and toward the poles.
You could use a weather vane
You really should be more specific. Are you talking about the group "One Direction" or the weather and even if you were specific your question still would make no sense. Sorry…
The answer is in the word, Westerlies blow out of the West.
The trade winds are the prevailing pattern eastern surface winds found in the tropics. They blow predominately from the Northern Hemisphere and the Southern Hemisphere.