Age of the ChildThe age of the child determines how quickly you can teach a child to swim. Because a child's motor skills, or what the child is capable of in terms of their development, will play a critical role in the student's progress. How quickly a child learns any sport skill is limited by their motor skill development. Naturally, as children get older their motor skills improve. So while a 3-year old may be able to learn to swim a distance of 15 feet with their face in the water in 25-30 lessons, a 6-year old may be able to learn the same skill in 10-15 lessons simply because the 6-year olds motor skills, due to his age, are further developed. While there are advantages starting later, for example, a 6-year old child may learn twice as quickly as a 3-year old. There are also disadvantages too, i.e., the child who learns at a younger age is usually "more natural and comfortable" in the water and obviously the child is safer in the water at that younger age.
Experiences, Frequency, Longevity, and DurationExperience also plays an integral role in how quickly you can teach a child to swim. Previous positive experiences in the water and additional practice opportunities will increase the child's improvement rate. While any previous negative experiences can certainly hinder the child's ability to progress at a normal rate.
The "frequency" or the number of classes per week also can be a significant role in progress. For young children, two to three session per week is superior to once lesson per week, unless of course, you discontinue lessons after two - four weeks. If your child is enrolled in swim lessons for 4 months per year at an average of two times per week that would equal 32 lessons. Those 32 lessons at twice per week will be more effective than 32 lessons in a once per week or four days per week scenarios.
Duration of a young child's class (especially 6 and under) should be kept to 30 minutes or less. 60 minutes of lessons per week divided into 2 classes is much more effective than 60 minutes per week all in one day. Not only is this true from a physiology standpoint, but also from a motivational one.