As far as the intentional ungrammaticality of the law' puS construction, as it is described in kgt is concerned.. Is someone allowed to make use of it regularly, or is it only to be used under special circumstances ?

It's a form of wordplay, which means it's appropriate whenever wordplay is appropriate. You probably shouldn't do it too often, or when there's the opportunity for confusion, or at a very formal occasion, or in a situation where beginners are learning.

Only the stuff in KGT, which involves substituting different words for the law' and puS, is called wordplay by Okrand; all the stuff from the HolQeD article about as Q as, not more Q than, and differently Q than is presented as ordinary grammar.

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SuStel
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