Not really. Eventually you are going to have to actually hit something. Even a partner holding a pad or something. Actually hitting something will tell you a lot about your kick. Most people have to practice to make sure the kick goes into the target as opposed to slide up along the target for example. Your kick will have less power if it comes in at an angle. A bag can also tell you about your power and speed of your kick.

You can. But no, it is not nearly as effective. You need to get a feel of what is like to actually hit something. A close second is a sparring partner with a chest piece. However, for power nothing beats a heavy bag and for target practice nothing beats a XL bob.

I could rant on and on, but the short answer is, GET A HEAVY BAG!

You can get balance and body mechanics of moving around, but it will be based on NOT hitting anything. Next time you get to a heavy bag, go ahead and kick it with the top of your foot, toes pointed as hard as you can. See how the rest of your month goes.

You can but it will not be that effective. If you don't have a target (heavy bag) then it is not effective. With a target you can get your aim and balance better.

Try to get an MMA instructor.

Si

nope only great martial artist like me can do that

Use a makiwara

...but get someone to show you how to use it

Is it effective to train taekwondo without a heavy bag or any sort of bag ....for example can you train by just kicking in the air and punching in the air and will it be as effective as having a heavy bag?