This paper describes WriteAhead, a resource-rich, Interactive Writing Environment that provides L2 learners with writing prompts, as well as ”get it right” advice, to helps them write fluently and accurately. The method involves automatically analyzing reference and learner corpora, extracting grammar patterns with example phrases, and computing dubious, overused patterns. At run-time, as the user types (or mouses over) a word, the system automatically retrieves and displays grammar patterns and examples, most relevant to the word. The user can opt for patterns from a general corpus, academic corpus, learner corpus, or commonly overused dubious patterns found in a learner corpus. WriteAhead proactively engages the user with steady, timely, and spot-on information for effective assisted writing. Preliminary experiments show that WriteAhead fulfills the design goal of fostering learner independence and encouraging self-editing, and is likely to induce better writing, and improve w...