On one hand, the main disadvantages of teaching children another language at primary school are that - firstly, it could affect their ability to learn their mother tongue properly and they might get confused by learning many different languages with different grammar and pronunciation at the same time. Secondly, it could be a waste of their study time which could be spent on learning core subjects such as mathematics, sciences, technology etc. Finally, the learning of foreign language adds more loads on these young kids and takes some of their fun time.