The descriptive linguist simply describes languages, all kind of languages, and all types of dialects of any language. If any judgements are to be passed upon the acceptability or so-called correctness of some usage, these are left either to the anthropologist or sociologist for an objective statement of the factors in the society which make certain persons more socially prominent and hence make their speech more acceptable, or to the man of the street, who is thoroughly accustomed to forming judgements upon the basis of his own egocentric attitudes and limited knowledge.
- Nida (1949), a pag.2

As descriptive linguists we need not be concerned about explaining the 'why's' of certain forms. [...] We cannot 'explain' the reasons for [...] difference, but we can define the distribution of these forms [...]
- Nida (1949), a pag.15-16