Try to turn the crankshaft pulley in a clockwise direction, using the ratchet on the center bolt. If the pulley turns, your engine is not seized. If the pulley does not turn, your engine is seized -- likely because of either pistons seized in the bores, or the crankshaft seized in the main bearings.
What are the signs of a seized engine?
There are almost always signs that can indicate potential seizing or failure such as: knocking noises, poor engine performance, oil light is on, and more. At the end of the day, most engine failure is because of poor maintenance, specifically a lack of oil in your engine.
What happens when you try to start a seized engine?
When an engine seizes and can no longer move, the starter will still attempt to crank the engine when the key is turned. Because the starter cannot turn the motor, the electric wires can overheat and begin smoking, a tell-tale sign of a seized engine.