2. The elliptical adverbial clause of time; as, “St. Patrick, when a boy of twelve, lights a fire with icicles.”—Froude.

In discussing adverbs as modifiers of nouns in Chapter XXX, we found that an adjective clause is frequently abridged to an appositive phrase in which the base-word, or noun in apposition, is modified by an adverb. A sentence like the following might have arisen in such a way,—“St. Patrick, then a boy of twelve, lighted a fire with icicles.” Here we have an abridgment, but it is unnecessary to supply any ellipsis, for we may say that the adverb then modifies boy of twelve. But in the sentence quoted we have not the simple adverb then, but the subordinating connective when. In order that it may perform its ordinary and proper function in the sentence, we supply after it the two words he is, making a regular adverbial clause of time, when he is a boy of twelve.

3. The elliptical clause of manner; as, “A great city sprang up as if by magic.” This construction has been spoken of in the chapter on prepositional phrases. It resembles the elliptical time clause in that the connective as if is a subordinating connective and needs a complete proposition following it. In the sentence quoted we must therefore supply the words it sprang up.

In the elliptical modal clause the connective is often the one word as, though it generally has the meaning of as if; as, “On that I found scratched as with a nail or fork, the following inscription.”—Holmes.

4. The elliptical adverbial clause of condition.

(a) An omission of the connective and the subject; as, “This frame of mind was the great exploit of our voyage, take it all in all.”—Stevenson. Expanded for analysis this clause becomes, “if we take it all in all.”

(b) An omission of the subject and the verb. This is found in the familiar expression if possible, which is really if it be possible, also in such sentences as the following,—“What is the use of health and life if not to do some work with them?”—Here we may supply after if the words the use is or it is.

5. The elliptical adverbial clause of concession.

(a) An omission of connective and subject; as, “Do what we may, summer will have its flies.”—Emerson. In this sentence the verb do is also to be supplied after the auxiliary may. Expanded the clause reads, though we do what we may do.

(b) An omission of subject and verb, the latter being a copula; as, “Solitude, though silent as light, is, like light, the mightiest of agencies; for solitude is essential to man.”—De Quincey. Since the noun solitude immediately precedes the clause as subject of the principal proposition, the clause is perfectly clear without even the pronoun it for a subject, and the verb is is easily understood. Only the new and necessary ideas need be expressed and these are the attribute silent as light. The base of such an attribute is not always an adjective; it may be a noun, a participle, or a prepositional phrase.