Sentences" are the most important structural units of every language. So the first thing everyone must learn at the beginning of learning a language is getting to know the rules of writing sentences. In this book, the rules of writing sentences have been cited from simple sentences to the complex ones. While trying to teach new vocabularies. The writer has introduced different exercises to help the readers deepen their knowledge of Persian language. This book is written in a way that serves as a textbook for both basic writing and teaching Persian language.