it is probably your freeze plugs
Look at the oil on the dipstick. If you have antifreeze leaking into the crankcase the oil will be milky.
Need to check the back to corners on the intake, they our none for leaking. There is 2 freeze plugs in the back of engine between the bell houseing and block.
you might have a blown head gasket and the coolant is leaking into the cylender and the engine is burning it.
Most likely cause is the intake manifold gasket-antifreeze will usually leak down the back of the engine and drip off of the starter or somewhere in that area.
Usually a leaking hose into or out of the water pump (depending on its location), or the water pump gasket.
Possible leaking hoses or water pump
Either one of the heater hoses are leaking or you have a freeze plug on the side of the engine leaking.
Not knowing what year, make, model and engine you have I can only guess that you may have a rotted out welsh plug on the back of the engine block.
look on the ground and follow it straight up to the engine
Most of the time it is because the water pump is going out and it is leaking where the pulley is on the engine.
Your car shouldn't "burn" antifreeze. If it actually is "burning" antifreeze then chances are you have a blown/leaking head gasket or possibly a cracked engine block which allows antifreeze to enter the combustion chambers. If your antifreeze is just disappearing then it is probably leaking out from somewhere. Possible leak areas to check out would be the radiator hoses, heater hoses, radiator, water pump, and the heater core. Most of the time if the heater core is leaking you'll be able to smell the antifreeze inside the car while the engine is running and the heater is on.