If the language is still developing, such as about three years old, it may be normal for some children to pronounce incorrectly. Parents can guide their children with correct pronunciation and encourage them to practice more.
Some pathological factors may lead to inaccurate pronunciation, such as hearing impairment caused by congenital cleft palate (in some cases, pathological factors are not easy to find), but there are generally many phonemes. Of course, sometimes parents may only distinguish obvious inaccuracies. Therefore, it is necessary to listen to the child's pronunciation in a concrete and comprehensive way to judge.
G and K are root sounds of the tongue, which are relatively difficult to pronounce, possibly because of insufficient muscle strength or uncoordinated pronunciation organs.
Generally, if it is a pathological factor, we need to solve the pathological problem first. If the dysfunction is caused by non-pathological factors, we can directly correct the speech.