In the following sentences the underlined words are examples of the nominative absolute construction:
The summit having been reached in record time, the climbers began the difficult descent to base camp.
Her parents having given their consent, Jane decided to spend her gap year in Australia.
In the end William was appointed, all the members of the committee agreeing that he was by far the best candidate.
Every afternoon, her domestic duties permitting, Eliza would go for a walk in the grounds of the big house.
As these examples show, the nominative absolute construction essentially consists of a noun (or pronoun) and a participle in agreement with one another, but neither of them in agreement with any word in the rest of the sentence. The nominative absolute construction is so called because the noun-and-participle phrase, which is usually separated from the rest of the sentence by a comma or commas, is grammatically independent of the rest of the sentence; and because the noun (or pronoun) in the phrase is considered to be in the nominative (or subjective) case: if a pronoun takes the place of a noun in the phrase, the nominative form must be used, as in ‘Harriet had worked on her own in the shop for many years and so now, she being too old to continue and no one else volunteering to take over, closure was inevitable.’
After the summit had been reached in record time, the climbers began the difficult descent to base camp.
Once her parents had given their consent, Jane decided to spend her gap year in Australia.
In the end William was appointed, as all the members of the committee agreed that he was by far the best candidate.
Every afternoon, if her domestic duties permitted, Eliza would go for a walk in the grounds of the big house.
It is clear from these examples that a sentence containing a nominative absolute phrase is generally less clear than the same sentence with the nominative absolute phrase replaced by the corresponding subordinate clause. This is because the conjunction which introduces the subordinate clause – in the above examples ‘after’, ‘once’, ‘as’, and ‘if’ - makes explicit the relationship between the content of the subordinate clause and the content of the main clause, whereas with the nominative absolute construction the nature of this relationship is a matter of inference.
The nominative absolute construction is rare in spoken English and not especially common in written English. See, e.g., The Oxford Dictionary of English Grammar, p. 4: ‘Except for a few set phrases (weather permitting, present company excepted) absolute clauses tend to be formal and written.’
The English nominative absolute construction is modelled on the ablative absolute construction in Latin, a construction in which the noun (or pronoun) and participle in the relevant phrase are put in the ablative case, e.g., Henrico regnante, multi peste perierunt (literal translation, ‘Henry reigning, many died of the plague’; or Iuvenes veste posita corpora oleo perunxerunt (Cicero, Tusculan Disputations I 47, 113), literal translation ‘The young men, their clothing having been laid aside, anointed their bodies with oil’). The ablative absolute is a more natural construction in Latin than the nominative absolute is in English.