My engine has seized.
A few things to check before you condemn the engine. Sometimes a coolant leak can get into the cylinders of the engine when it is sitting. This will hydro-lock the engine. Water above the piston does not compress and will stop the engine from turning. One last thing is to remove the drive belt(s) and try to turn over the engine. A seized alternator or AC compressor can prevent the engine turning as well. YourMechanic does not replace or rebuild engines, but we could verify whether the problem is engine failure or something else.