He is in kindergarten and the youngest one in the class. He talks a lot and didn't follow directions at begining. One day I got teacher's email said she hardly can handle him during the week. I talked with his teacher and did volunteer at his class to see what is the problem. I think for the young boy, some of them maturate slower than girls. You need to remind him all the time. Set up some rules at home and let him to get use to follow directions. It takes time for them to learn. I just fell that my son didn't understand why he needs to follow the order(even he has been in the school for last two years). After three months training, my son is getting better now.
1. Some teachers are really restrict about following the rules like my son's teacher. Maybe your son's teacher also like that. Even though you think your son changed a lot, maybe it is just not enough for the teacher.
2. Take it easy from your part. They are only 5-year old, there are plenty of time for them to learn. I noticed that when my son was in preK, the first semester, tearcher told me that my son was disturbing the whole class. But in the second semester, he was OK.
3. Keep in touch with the teacher, sometimes they like to complain and if they didn't hear from you they might get upset and thought you ignored that even you already taught you son at home. Talk with the teacher when you drop off or pick up your kid. Volunteer is another way to do .
4. One thing is different, my son's teacher is really restrict in the class. But she is nice after school.
5. For Chinese parents, sometimes we don't have same topic to share with other parents and teachers, that makes a distince between you and teacher. I just try to chat with her shortly when we met, so we won't feel uncomfortable with each other. You also can explain that why your son has those problems and ask her for suggestions (it may make her happy if you ask for her help).
6. kids will meet all kinds of teachers during their school year so do we. Both of us(kids and parents) need to learn how to fit in different situation together. Changing the class or even the school might not be helpful. How do you know next teacher is good or just same as this one? Unless there is a serious problem and your son refuse to go to school or he is really unhappy about schooling, then you might want to move him to somewhere else.
Don't worry, take it easy. This is not the problem for you only. A lot of parents espacially foreign parents are facing the same thing because we are not familiar with the culture here. We learn it with our kids together.