1 We have to be polite to each other
2 everybody has to do a special duty (mom has to do the cooking, dad has to do shopping, I have to clean everybody's shoes, my sister (brother) has to do washing up)
3 We have to be at home by the time of supper - in order to have it together.
4 We do not have to share things if we do not want to do that
5 We need not tell lies to each other - we are an understanding family))
Достаточно?