Some observations:
1) N't-negation is dominant in conversation (69%) while not-negation accounts for
nearly half of the negative forms in writing (47%);
2) The contracted negative form n't always takes an operator, i.e. an auxiliary or modal
verb whereas the full form not does not. We examined 1,000 concordances randomly
sampled for not and n't each in FLOB and BNCdemo, and found that n't is always
enclitic to an operator with no exception in both writing and speech while only about
two thirds (66.7% in FLOB and 63.8% in BNCdemo) of the total occurrences of not take
an operator.
3) A full operator followed by not (type c) typically occurs in written genres (with a
FLOB/BNCdemo ratio of 8.8:1), where text categories D, B, J, G, H and F account for the
majority of this form.
4) A full operator plus n't (type b) is more common than a contracted operator plus not
(type a). The former occurs in conversations as well as in written genres
(FLOB/BNCdemo=1:6.9, typically in five types of fiction plus humour) while the latter
normally occurs in conversations (cf. Biber et al 1999: 160; FLOB/BNCdemo=1:12.4,
typically in five types of fiction plus humour).
