Question

Why doesn't food enters the trachea instead oesophagus?

Answer 1

Because of Epiglottis.Epiglottis ensures that food doesn't enter into trachea (lungs), & so while eating our breathing stops few seconds because epiglottis stops the passage way to trachea (lungs), so this is the reason because of the presence of special structure called epiglottis, food doesn't enter into trachea the wind pipe.
Hope it helps.

Answer 2

The food enters in the oesophagus instead of trachea because the trachea is a pipe through which the air is enters in the body. There is a seperation between trachea and oesophagus due to which the food enters from oesophagus and air enters through trachea.