Contents › Section 2: Morphology, Syntax, Lexicon › answer 15 of 37
Sentence well-formedness
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In fact, you can remove pretty much and preserve grammaticality if you don't care about preserving meaning. The more the easier. "Go!" is a fully formed, perfectly grammatical English imperative sentence. So is "In!". The confusion comes from the well-formedness paradigm of formal linguistics and is not a real concern.
However, if you wanted to preserve some basic semblance of what the sentence was about, and you started out with a sentence with a finite verb in it, in English, you need at least the subject, the verb and whatever obligatory phrasal elements there are. So Elephants snore. or Elephants drink water.
© Dominik Lukeš. Licensed under CC BY-SA 3.0. Originally published on Linguistics Stack Exchange, attributed there to Dominik Lukes (profile).