In language, first graders are taught the fundamentals of literacy, including reading sentences, writing very simple statements and mastery of the alphabet, building on what the students have learned in kindergarten or other forms of pre-school (although because first grade is the first compulsory level of education in many U. S. states, the level of literacy in incoming students can vary widely). The expectations for first grade have changed due to the Common Core Standards. Curriculum is typically based on state standards developed by educators in each state. Most states use the Common Core Standards, so most schools across the country are using similar curricula. First graders are now expected to read and comprehend stories ranging in lengths and difficulty. They are also expected to show an improving fluency rate during the school year with ability to easily read stories by the end of the year.