When people practice simple word classification tasks before nodding off -- knowing that a 'cat' is an animal or that 'flipu' isn't found in the dictionary, for example -- their brains will ...

All words belong to a word class. It’s that word’s type: nouns, verbs, adjectives, adverbs, pronouns, prepositions, conjunctions, determiners and exclamations. These are all word classes. Consider the ...