Mary lives in a town. (-) The town is big and nice. (-) She goes to school. (общ.) She is a good pupil. (общ.) Mary is seven. (спец.) She can read well. (спец.)
Mary doesn't live in a town. The town isn't big and nice. (общ.) Does she go to school? (общ.) Is she a good people? (спец.) How old is Mary? (спец.) How can she read?