I joined swimming and learnt to float within four days...suddenly I discontinued for 16 days as I had fever-related problems. Other people in my group might have already learnt to swim these days. How long will it take me to learn to swim?
Learning to float in 4 days is a fine achievement, and this tells me that you may be able to learn to swim in only a short time.
It is impossible to say how many days it will take you to learn as we are all different and learn different skills at various speeds. However, the fact that you have become comfortable with floating in the water means that you have no fear of the water and can relax.
Relaxation in the water is essential to learning to swim. Your next steps are learning to hold your breath and submerge, stop, and stand up mid-swim. Once you have learnt these stages, kicking with your legs and pulling with your arms will be easy!
It is not important if the others in your group have learnt to swim, but how well you learn to swim. If you have recovered from your fever-related problems, you can continue the good progress you have already made.
For you some extra help with learning to swim, you can download my eBook The Complete Beginners Guide To Swimming. It contains pictures and exercises on how to submerge, stop and stand mid-swim and swim the four basic swimming strokes. You can download it instantly, print out the parts you need and take it to the pool to try out.