There are multiple possible scenarios here.

• Lens without internal motor (AF line, including AF-D series and a minority of G-type lenses): Modern low-end cameras can't focus these, even though they can assist you if you enabled the option found in Settings>Rangefinder. You must flip the on-lens switch to M to disconnect the AF coupling gears before the focusing ring will turn (assuming the lens isn't broken!!)

• Cheapest AF-S lenses (all kit lenses except the 18-105) and old AF-I lenses: Can autofocus on every Nikon DSLR if the focus style in the quick menu (<[i]> button) isn't set to MF. They still feature a traditional focusing ring which is rotated by the motor and thus disabling AF with that option won't enable manual focus unless the mechanics are disengaged via the on-lens switch.

• Modern mid-grade to high end AF-S lenses: Soft touch, "endless", not-turning-during-AF focusing ring and M/A-M switch: can focus manually in any mode, and automatically if AF is enabled on both the lens and the camera (see above). Rotating the ring during AF operation will stop the motor.

• AF-S DX VR 18~105:3.5~5.6G ED IF: An odd breed of the previous case where the AF disable switch selects A-M: focus can be adjusted manually at any time but will not cancel motor operation and enable shutter release even after AF fails. It becomes possible for the user to literally fight against the motor (not recommended!)

• Top of the line AF-S lenses: A combination of the two previous scenarios, with a 3-position focus switch alternating between A/M, M/A and M.