It's been 7 months now and although he likes going to school he doesn't really play with the other children and won't talk to anyone including the teachers. When asked a question by the teacher he'll either point, shake his head or whisper. He's the complete opposite at home . Many children outgrow it with understanding and acceptance from their parents. Talk about it with him and discuss how he feels at school.
Different children respond to different teachers.
Try having a conference with the teacher and the director of the school and ask them how they are going to handle the situation. Something that they can do is to ask him if there is any way that they can make him feel more comfortable. They shouldn t force him into situations that he isn t ready for like performing or singing in front of others. If you are still concerned, it can t hurt to take him to get evaluated by a professional. Once they have indicated that there is no physical problem, relax.