The thought “Learning English at school is a waste of time” is rather disputable. I feel quite strongly that English is the necessity of today’s life. But, of course, you should ask yourself whether it is necessary for you or not, and why. Based on the answer you may generally define its priority. On the one hand, you must spend much time and make all efforts for learning English. You may say that learning English at school is a waste of time. On the other hand, learning English at school is free. You should not miss such opportunity. So it's up to you to decide. To my mind, learning English at school isn`t a waste of time. English at school is worth learning.