In this book John McKenny explores the nature of the argumentative writing of advanced learners of English. Having compiled a representative corpus of essays by university students throughout Portugal in the mould of the International Corpus of Learner English (PORTICLE), he compiled a Corpus of Experts (CofE) comprising editorials from broadsheet newspapers in the UK and US which would represent accomplished L1 writing. He used a sub-corpus of LOCNESS to represent the argumentative writing of American undergraduates and a sub-corpus of BAWE to represent good writing by British students. These 4corpora form a spectrum of writings ranging from L2 learners (PORTICLE, L1 learners (LOCNESS) to proficient L1 writers (BAWE) and expert writers (CofE). Certain tendencies emerged when the use of formulaic sequences (FS) were investigated. The L2 learners greatly overused certain FSs (e.g. I think) and used fewer types of FSs. One explanation of this overuse is the so- called "teddy-bear effect". After characterizing the phraseological competence of L1 learners in comparison with L2 writers, ways of helping them produce more natural language are suggested.