Affirmative sentences are statements that express a positive assertion or fact. They typically follow a subject-verb-object structure, such as in the sentence “The cat chased the mouse.” These sentences confirm that something is true or happening, making them essential for clear communication. In English, affirmative sentences can be simple or complex. For example, “She loves chocolate” is a simple affirmative sentence, while “They will go to the park tomorrow” is more complex. Using affirmative sentences helps convey information directly and effectively, allowing for better understanding in conversations and writing.