  We analyze the frequency-rank relationship in sub-vocabularies corresponding
to three different grammatical classes (nouns, verbs, and others) in a
collection of literary works in English, whose words have been automatically
tagged according to their grammatical role. Comparing with a null hypothesis
which assumes that words belonging to each class are uniformly distributed
across the frequency-ranked vocabulary of the whole work, we disclose
statistically significant differences between the three classes. This results
point to the fact that frequency-rank relationships may reflect linguistic
features associated with grammatical function.
