If I know how to ride a motorcycle will it be easy to learn a stick shift car?

Riding a motorcycle makes it easier to lean how to drive in general. I have taught 7 kids to drive. 4 Rode before they drove and 3 did not. The ones that rode first caught on much quicker and frankly still drive better today.

Completely unrelated shift operations... one has gear with hand and the other has gear with foot, one has clutch with foot and the other clutch with hand. Apart from teaching you a bit about engine speed and gears, there is not much in common. So learning a bike will not make learning a stick shift any easier. Not that it's hard, outside the US most people learn stick shift and don't drive automatics.

The same principles will apply; i.e. clutch, shifting, etc. You will likely find it easier.

Not really except knowing when to shift, maybe you can use your foot instead of your hand

For me, i did the opposite, I learned how to drive in a car first, then went to the bike, I got a hang of it within 10 minuites, knowing the one definitely helps learn the other, you should pick it up fast.

The mechanics and principles are absolutely identical. On a motorcycle you operate the clutch and throttle with your hands and shift with your foot. In a car, you will be operating the clutch and throttle with your feet and shifting with your hand. The only thing you will have to adjust to is the new locations of the controls. I had been driving a stick for years when i rode a motorcycle for the first time and i took off for the first time on a motorcycle effortlessly from a resting position up to about 75mph in 6th gear and then back down to a crawl without putting any conscious thought or effort into shifting. Ive been riding a bike of my own ever since and have never stalled or over-revved it. If you start learning how to operate a manual transmission on a motorcycle, you may still have issues driving a stick shift car, but not because they behave differently, just because youre still learning to operate a manual transmission.

Both vehicles have a shifter, a clutch, and several gears. The rate at which you release the clutch on either vehicle must correspond to your use of the accelerator; otherwise, the vehicle might stall or lurch. However, the controls are different. The motorcycle's accelerator is the right-side handlebar grip; the clutch is operated with the left hand, and the left foot operates the shifter. The car's accelerator and clutch are operated by pedals using the right foot and left foot respectively; and the shifter is operated by the right hand. Therefore it will not be simple transition from motorcycle to car. On the other hand, your experience with a manual transmission on the motorcycle should enable you to learn to drive the shift-stick car more easily.

Learning to shift on a motorcycle will teach you the fundamentals of driving a manual transmission. You will then just need to learn to clutch with your foot and shift with you hand instead of the opposite.

it's quick to learn. You just have to go do it!