This document discusses principles for teaching writing to first and second language learners. It begins by defining writing and outlining the historical development of writing instruction, moving from rigid rule-based approaches to process-based and genre approaches. Key principles discussed include using meaningful input and output, focusing on language and fluency, designing appropriate tasks, emphasizing reading, and providing helpful feedback to improve writing. The conclusion advocates applying research-supported principles like these to effectively teach writing as a foreign or second language.