ABSTRACT
When we begin to study something unknown, one of the ways that we try to make sense of it is by grouping or classifying the different phenomena that we encounter. The same was true when people first started thinking about and describing languages: they looked at the basic units – the words – and tried to find ways of putting them into groups or classes. Indeed, in the past this approach was almost the only one used in describing grammar, and it is still important, though we need to supplement it with other approaches.
