Three Models for the Description of Language

4 Inadequacies of phrase-structure grammar

1. How does Chomsky analyse the English auxiliary system?
   Verb → Auxiliary V; Auxiliary → C (M) (have en) (be ing), with M a modal and C past or present: one obligatory element and optional ones in fixed order. Discontinuous pieces (have…en, be…ing) then combine freely.
   • Chomsky, 1956, Three Models for the Description of Language (IRE Transactions on Information Theory), §4
2. Why does the affix-hopping rule go beyond phrase-structure grammar?
   The rule Af v → v Af # (moving each affix after the following verb-like element) uses discontinuous elements and must know that e.g. “take” is a V: it needs the constituent structure (the derivation history) of the string, not just the string itself.
   • Chomsky, 1956, Three Models for the Description of Language (IRE Transactions on Information Theory), §4
3. Why did Chomsky remove be + en (the passive) from the auxiliary rule?
   It doesn’t combine freely: it can’t occur with intransitive verbs (“John has been come”), is excluded in the context “the man — the food” and required in “the food — by the man”. Removing it and adding a passive rule makes all these restrictions automatic.
   • Chomsky, 1956, Three Models for the Description of Language (IRE Transactions on Information Theory), §4
4. State Chomsky’s passive rule.
   If NP1 – Auxiliary – V – NP2 is a sentence, so is NP2 – Auxiliary + be + en – V – by + NP1: “the man – past – eat – the food” gives “the food – past be en – eat – by the man” → “the food was eaten by the man”.
   • Chomsky, 1956, Three Models for the Description of Language (IRE Transactions on Information Theory), §4