Along the way you get worked examples with the key words marked, before-and-after fixes that show why the first version loses marks, a one-page visual summary, word cards with meanings and examples (I would be grateful if, Would you mind, Could you possibly and do me a favour), a quick check to test yourself and a recap of the rules to remember. Each card holds one idea, so you can read it on a phone between practice sessions.
Reading it online is free: create a free BandLadder account and the whole lesson opens in our study reader, on the web and in the app. Downloading the PDF to keep needs a plan; the free reader has every card.