Reading the values of an AC motor

Hey so wondering how i can read the values of an AC motor. So lets say that i have an esc and i can control the motor with the arduino. but is there any way i can spin the motor by hand and have the arduino read or detect that it was span?

AC motor - they are several types. ESC - that's normally for DC motors.

Can you say what kind of motor?

Ask you grasping for the concept of an encoder? Or even field-oriented control?