Is it good to learn swimming underwater only?
I only picked up swimming last year by starting to learn swim underwater. I don’t know how to swim in freestyle & breaststroke neither until know. I learned swim underwater by observing others & practice on my own. Just wonder can I consider myself know swimming by just know swim underwater?

Most children learn to swim underwater on their own because it is easier to sink than to keep yourself above the water. Make it a point to get better at swimming with your head above the waterline. Technically you CAN swim but you are doing yourself a lot more good if you learn to swim above water as well. Swimming under water usually occurs because the swimmer in question cannot hold his or her head above the water in a buoyant position. Those swimmers usualy put their feet down to take a breath and cannot tread or stay afloat. This is a very risky situation because it provides a false sense of confidence in the underwater swimmer if you say he or she CAN swim. Technically yes, that person can propel him or herself through the water. However, it does not necessarily mean that person has the skills to stay afloat in deeper water and take the necessary breaths. Do yourself a favor and learn to surface swim.
Good luck!