Collins COBUILD English Grammar (1990)

Fourth edition, 2017 COBUILD's grammar is built on evidence of how English is really used, drawn from the 4.5-billion-word Collins Corpus, so its examples sound like things people actually say and write rather than sentences made up to fit a rule. It is aimed at learners and teachers, and its explanations stay simple. Pick it over Practical English Usage if you want grammar organized as a system rather than as a set of problem entries. It sets out the key differences between British and American grammar, and two supplements cover the academic and business contexts where many adult learners use English most.