This compound complex sentence consists of two complex clauses, joined by the coördinate conjunction but. In each of these, the subordinate clause is compound ([§ 521]), consisting of several coördinate adverbial clauses introduced by relative adverbs (while in the first, when in the second).
4. The clear and agreeable language of his despatches had early attracted the notice of his employers; and before the Peace of Breda he had, at the request of Arlington, published a pamphlet on the war, of which nothing is now known, except that it had some vogue at the time, and that Charles, not a contemptible judge, pronounced it to be very well written.—Macaulay.
In this compound complex sentence, the first coördinate clause is simple, the second is complex. In the second, the adjective clause of which nothing is known has dependent on it the group of words except ... well written, consisting of the preposition except and its object (the compound noun clause, that ... time, and that ... well written). This group serves as an adjective modifier of the noun nothing. The whole passage of which ... well written forms a complex adjective clause, modifying pamphlet. It to be very well written is a complement, being an infinitive clause used as the object of pronounced ([§ 325]).
CHAPTER VIII
ELLIPTICAL SENTENCES
527. Good usage does not demand that all sentences shall be absolutely complete. It often allows (and sometimes requires) the omission of words that, though necessary to the construction, are so easily supplied by the mind that it would be mere waste of time to utter them.
528. The omission of a word or words necessary to the grammatical completeness of a clause or sentence is called ellipsis.
A clause or sentence that shows ellipsis is said to be elliptical.
Ellipsis is a Greek word meaning “omission.”
In the following examples the omitted words are supplied in brackets.