Popular custom would have you think that kids are effortless second language learner & far superior to adults in their eventual success. To start with, childrens wide spread success in obtaining second language belies an brilliant unconscious work dedicated to the task. The difference between kids & adults lies primarily in the contrast between the childs spontaneous, peripheral attention to languages forms & the adults overt, focal awareness & attention to those forms. Therefore, the popular notion about kids holds only if effort refers, narrowly, to focal attention language forms.
Nor are adults necessarily less successful in their efforts. Studies have shown that adults, in fact, can be superior in number of aspects of acquisition. They can learn & retain a bigger vocabulary. So, while kids, with their fluency & naturalness, are often the envy of adults struggling with second languages, kids in classrooms may have some difficulties learning a second language.
Third, the popular claims fail to differentiate young kids from pre-pubescent kids & whole range of ages in between. There's actually lots of instances of older (school-age) kids manifesting significant difficulty in obtaining a second language for a giant number reasons. Rating high on that list of reasons are lots of complex personal, social culture, & political factors at play in simple school teaching of second language.
To successfully teach kids a second language requires specific skills & intuitions that differ from those that you would use for adult teaching. categories may help to give you some practical approaches to teaching kids.