English modal verbs are claimed to be declining in their
use in English (Leech 2011, 2013; inter alia), an assertion that is
essentially based on aggregate frequencies of modals across register and time (Biber 2004). Since modals may be viewed as a
prime example of paradigmatic organization (e.g. Diewald 2009; Diewald
& Smirnova 2012), it seems only plausible to seek a generalization
regarding their overall development. This approach, however, comes with a drawback,
namely that it neglects the modal system’s underlying heterogeneity. By utilizing
both historical and contemporary language data from COHA (Davies 2010) and COCA (Davies 2008), I will argue that the obvious variability in the
English modal system represents an important caveat against making generalizations
across an entire category in terms of frequency shifts.