How to sign the letter M in ASL

A fist with the thumb tucked under three fingers (index, middle, ring), peeking out between the ring and pinky fingers.

Easy to confuse. N tucks the thumb under only two fingers (between middle and ring). S wraps the thumb across the front of all fingers.

M is one of the six fisted letters - A, E, M, N, S, T - that differ only by where the thumb sits. You cannot check these on yourself, which is what the camera is for.