Hybrid powertrain with a single planetary gear, a single motor / generator, and three or more operating modes

A hybrid powertrain includes an engine, an input member, an output member and a stationary member and comprises a single planetary gear set having a first, a second and a third element. The input member is connected for common rotation with the engine, and the output member is connected for common rotation with the second member. A single motor / generator is continuously connected for common rotation with the third member. A starter motor is operatively connected to the machine to start the engine. A first torque-transmitting mechanism is selectively engageable to connect the input member for rotation with the first element. A second torque transmitting mechanism is selectively engageable to establish the first element to the stationary member. A third torque transmitting mechanism is selectively engageable to establish the third element to the stationary member. The drive train is operable in an electrically-only mode of operation, only one machine operating mode, and an electrically-adjustable mode of operation.