the persistence of syntax

[Lionel Mandrake]

Syntax seems to change more slowly than semantics. For example, modals in English have had about the same syntax for hundreds of years, but what used to be their preterites now have present-tense meanings. The obsolete verb 'mote' meant "must" during (and before) the Early Modern period, and its formerly-preterite form 'must' is all that remains of it. The other modals come in pairs (may/might, can/could, etc.) such that the formerly-preterite forms are often called subjunctive nowadays.