By Mark Amery —

Two inconsistencies in English native speakers tend not to notice

An odd thing about modal (and "semi-modal") verbs in English that is natural to native speakers but completely illogical: sometimes putting "not" after the modal verb negates the modal verb itself, and other times it negates the main verb. For instance, consider these sentences:

  • You may go.
  • You may not go.
  • You must go.
  • You must not go.
  • You need to go.
  • You need not go.

Clearly "You may go" is not synonymous with "You must go" - the former grants permission and the latter issues a mandate. But the versions with "not" both express prohibition, and mean exactly the same thing. Meanwhile, "You need to go" is synonymous with "You must go" (both expressing a mandate), yet once we add "not", we get two different meanings (when expressing a prohibition, the other expressing permission not to go). Should we not find this surprising?

As native speakers we unconsciously understand that the "not" attaches to a different verb in each case - that it negates the "may" in "You may not go" and the "need" in "You need not go" but negates the "go" in "You must not go". But what an arbitrary rule! A learner of the language surely must find this inconsistency puzzling when they first encounter it!

A further oddity is that, when adding adverbs, we can (but don't necessarily) flip to the alternative meaning of "may". Consider:

  • "You may absolutely not go." - same meaning as "You may not go", just emphasised the "absolutely" and "not" both attach to "may", not to "go". But...
  • "You may freely not go." - now the "not" modifies "go", and we have a permission-granting sentence!

And yet a further oddity is that, when "may" is used in the sense of expressing possibility rather than permission, "not" attaches differently:

  1. It may not rain (possibility)
  2. You may not smoke (permission)
  3. You may not survive the procedure (possibility)

(Consider what the meanings would be if the "not" attached to the other verb in each case. Sentence 1 would mean that it will definitely not rain; sentence 2 would mean merely that you have permission not to smoke (i.e. that smoking is non-mandatory; and sentence 3 would mean that the procedure is certain to kill you. Yet we native speakers suffer no confusion upon reading these sentences and instantly understand the correct meaning, because we have internalised - usually subconsciously - the rule that the "not" attaches to "may" when used in its permission-granting sense, and to the main verb when "may" is used to denote possibility.)

"Shortly" (and "momentarily")

The following adjectives are all synonyms:

  • short
  • brief
  • momentary

One might therefore expect the adverbs derived from them - "shortly", "briefly", and "momentarily" - to be synonyms too. But of course, bizarrely, they are not; "briefly" means "for a short time", as you'd expect, while shortly means "in a short time", and "momentarily" might mean one or the other depending upon whether you're a Brit or an American.

Foreign learners surely must scratch their heads at this too. And I can offer them no explanation for why things are that way; they just are. Indeed, quite possibly, the explanation for "shortly" is lost to time; sources don't even agree about what the word meant in Old English, let alone how it evolved to have the meaning it does today.