I urge my students to get a usage dictionary… To recognize that you need a usage dictionary, you have to be paying a level of attention to your own writing that very few people are doing… A usage dictionary is [like] a linguistic hard drive… For me the big trio is a big dictionary, a usage dictionary, a thesaurus — only because I cannot retain and move nimbly around in enough of the language not to need these extra sources.
As a teacher, about 90% of my job is getting the students to understand why they might need one.
A usage dictionary is one of the great bathroom books of all time. Because it has the appeal of trivia, the entries are for the most part brief, and you end up within 48 hours — due to that weird psychological effect — actually drawing on exactly what you learned in some weird, coincidental way.
– David Foster Wallace in Quack This Way