OUGHT TO in Middle English : a semi grammaticalization ?
In Present Day English (hence PDE), OUGHT TO is considered as a semi-modal,
something inbetween a lexical verb and a grammaticle item. Yet, that semi-modal,
like all the other modals, belonged in Old English (OE) to the same class of verbs :
the preterite present verbs.
As shown in Roméro (2005), those verbs all underwent the grammaticalization
process by the end of the OE period, along with the causative verbs and the particle
TO. However, in Middle English, AGEN still remains apart in that classification since
it is mainly followed by TO, which grammaticalized as well. At that period, we could
find AGEN as a lexical verb or as a modal verb (either followed by a bare infinitive or
the particle TO), as the examples show :
1. Det hit er ahte. That he already owned it. (CMLAMBX1,313.C2.1087)
2. Dt euch mon ahte hersumin & herien in eorDe. That each one ought to
obey and praise on earth. (CMKATH,23.75)
3. [Arthure] owen al De worlde TO deme. Arthur ought to deem all the
world. (CMPURVEY,I,52.2123)
Then we can question why AGEN followed a different path compared to its OE
classmates. In examples displaying TO, it functions as a control verb, and what
follows the particle is a CP, whereas the other modals are raising verbs followed by a
VP. Could we claim that the grammaticalization of AGEN and the grammaticalization
of TO cancelled each other out, like the negative concord process ? Or could we say
that, in this particular case, the process of grammaticalization of those two items is not
finished yet ? TO came to bear the subjuctive content of the dative-marked infinitive
that could follow it in OE, and OUGHT came to be read as a conditional, an irrealis
form and not a past form anymore. Moreover, we have found some examples where
AGEN was not reanalyzed as a modal, but TO was, and some other examples where
AGEN was reanalized but TO was not.
We shall then try and find out (within a Minimalist framework, and with the
help of Distributed Morphology) the relations which exist between these two items, in
comparison with the other modals, with time and tense, and with grammaticalization
to explain this very particular status OUGHT TO has in PDE.