Unfortunately, Guy Cook's book "Translation in Language Teaching" is not available for free download. However, you can find a preview of the book on Google Books or purchase a copy from online retailers such as Amazon.

Cook's approach to translation in language teaching is centered on the concept of "pedagogic translation." This type of translation involves using translation as a teaching tool to help learners understand and produce language, rather than simply translating texts for their own sake. Cook advocates for a task-based approach to translation, where learners are given specific tasks to complete through translation, such as summarizing a text or completing a gap-fill exercise.

If you're looking for free PDF resources on translation in language teaching, you can try searching online academic databases such as ResearchGate or Academia.edu, where researchers and educators often share their papers and articles on language teaching and translation. Additionally, you can also check online libraries and repositories such as the British Council's website or the Cambridge University Press's website, which offer free access to a range of language teaching resources, including PDFs and articles.