Subject predicate inversion due to negation
- All my cigarettes lit
- Not all my cigarettes lit.
The first sentence is a positive polarity declarative sentence. The Subject of the sentence is the noun phrase all my cigarettes. In the second sentence the predeterminer all has been negated by the adverb not. This is comparable to the use of the adverb almost in Almost all my cigarettes lit. However, the effect of premodifying the word all with the word not is to negate the whole sentence. We can show that the whole sentence has taken on a negative polarity, by adding a question tag to the end of the question. Positive sentences take a negative tag by default, and negative sentences always take positive ones:
- You liked the ice-cream, didn't you? (positive sentence, negative tag)
- You didn't like the ice-cream, did you? (negative sentence, positive tag)
- Not all my cigarettes lit, did they? (negative sentence, positive tag)
Now sentence (2) is entirely grammatical. There is no inversion required here at all. Now if there was an inversion here, what would it look like? The type of inversion cause by the pre-posing of negative adjuncts is Subject-auxiliary inversion. This is when the Subject of the sentence and the first auxiliary verb in the verb phrase change places:
- All my friends have been so happy.
- Never have all my friends been so happy.
Now in sentence (2) there is no auxiliary verb, which means that if we did want to carry out an inversion we would need to use the dummy auxiliary do. Now the Subject of the sentence is not cigarettes but as described above not all my cigarettes. This would give us:
- *Did not all my cigarettes light.
Of course, grammatically what we have here is a question, an interrogative sentence. This is not all that surprising because questions, after all, also use Subject-auxiliary inversion. However, a question is not what we were after. As an attempt at a declarative sentence the example is ungrammatical.This is a clue as to why Subject-auxiliary inversion is not required here, or in fact, is actually ungrammatical.
Subject auxiliary inversion occurs when a negative ADJUNCT (read adverbial) in the clause gets moved to the front of the sentence. An adjunct in this sense is a phrase that is grammatically 'extra'. In other words it cannot be the Subject of the verb or one of its Complements. It cannot be a word or phrase inside the Subject or Complement either. In sentence (2), the word not is part of the Subject. For this reason the fact that it is at the front of the phrase doesn't engender any inversion. In contrast, the adverb never in sentence (4) is a proper Adjunct. It is not part of the Subject. For this reason, Subject-auxiliary version is required. Notice that when this occurs, it is obligatory, not optional. The following sentence is not grammatical in standard English:
- *Never all my friends have been so happy. (ungrammatical)
The Original Poster's excerpt
The Original Poster asks about a specific excerpt from the poem Tree by My Window by Robert Frost:
Not all your light tongues talking aloud could be profound
This sentence has the same structure as Not all my cigarettes lit. The Subject of the clause is Not all your light tongues talking aloud. You will notice that this phrase comes before the auxiliary verb could. There is no Subject-auxiliary inversion here as we can see. The reason that the grammar won't allow an inversion here is that, as in the examples above, the adverb not is occurring within the noun phrase functioning as Subject. It is not an Adjunct in the clause structure.