Being a corpus enthusiast myself, the article caught my attention when I saw the objections of Michael Swan to the bandwagon approach in using corpora in the ESL classroom:
“Native English speakers have tens or hundreds of thousands — estimates vary — of these formulae at their command... a student could learn 10 a day for years and still not approach native-speaker competence."
I appreciate Swan's realistic appraisal, but it wouldn't do much for my confidence as a second language learner. It reminds me of what my Japanese tutor told me when I was beginning to learn kanji (Chinese characters):
What I really want to say is if you're a language learner, don't give up!