May
A month which promises much but so often disappoints.
A prime minister who did likewise.
A modal verb which, in the argot of a lawyer, expresses optionality, but is written “shall be entitled” or, if she wants to be bloody minded about stating the bleeding obvious (and which lawyer can stop herself being bloody minded from time-to time?) “may, but shall not be obliged to”.
See also
Plain English Anatomy™ Noun | Verb | Adjective | Adverb | Preposition | Conjunction | Latin | Germany | Flannel | Legal triplicate | Nominalisation | Murder your darlings