When I was in primary school, I did martial art's before I did badminton. The name of martial art I did was called “Hap Ki Do” I did it for about 1 year but I had to stop as I broke my shoulder during training. During the 5th and 6th years of primary school, I did enjoy badminton but it was purely as a special school activity one hour a week. No coach, no net, no court, no sports hall. It was played in the school playground. Just hitting a shuttlecock. I did not learn much badminton skills at all during this time.
There are two skills I remember I had been taught which was how feet position should be when I serve and pronate the forearm when executing a forehand drive. It was about 50 years ago but there are still many coaches that teach the same method of the forearm pronation. It is not a wrong technique to teach but not many coaches teach other types of drives which can be used in different situations. I have always felt that badminton is a type of sport which is not really studied but taught by the way that people have heard from other people. The real reasons for the skill and other alternative ways have not really been studied.
Other than playing badminton, I played a little bit of football and handball same time. I did not do anything really seriously there was nothing that I particularly enjoyed more.