An adverb clause modifies a verb. It contains a subject and a verb. As a dependent clause, it cannot stand alone and must connect to an independent or main clause to form a complete sentence. An adverb clause may come before or after the independent clause. When an adverb clause precedes an independent clause, a comma is used to separate the clauses. When the adverb comes after the independent clause, no comma is used. Adverbs indicate such things as why, where, when, and how. Typical adverbs in English are words like “soon”, “here” and “quickly”; adverbial phrases are groups of words used in the same way, such as “on Sunday” or “with compassion”. Likewise, an entire clause — remembers that a clause has a subject and predicate — may have an adverbial function: John is working so that she will notice him.[why]
John works wherever we want.[where]
Joan works after school is out.[when]
Joan works as rapidly as she can.[how]
Adverbial clauses are introduced by conjunctions. Whether there is a change of subject. If no change of subject is involved and a preposition exists which corresponds to the conjunction, that preposition plus an infinitive is normally used, e.g.: He's saving his money so he can buy a car. The type situation or time in the adverbial clause: in general, if the situation in the adverbial clause is viewed as something hypothetical or anticipated —rather than completed, habitual, or factual— then the subjunctive is required. In contrast, if the adverbial expression deals with something that is viewed as completed, habitual, or factual, the indicative is used. Some adverbial conjunctions by their very nature deal with something hypothetical or anticipated and thus are always followed by the subjunctive; others may take either the subjunctive or the indicative. I always brush my teeth after we eat. (indicative) I’ll brush my teeth after we eat. (subjunctive) Adverbial conjunctions which are ALWAYS followed by the subjunctive (because they always indicate a pending/hypothetical action or state): such as so that, unless, before, in case, without, etc.
I'm not going unless she comes.
I leave at 1:00 provided everything is done.
She works hard so they (can) live well.
I don't do anything without their knowing it.
Normally a preposition is used when no change of subject is involved; it is followed by an infinitive, not the subjunctive or indicative. Examples: I'll win before I leave [before leaving.]
My son lives to play the guitar.
The following adverbial conjunctions deal with time, and are followed by the subjunctive when they introduce an anticipated situation. If they introduce one which is viewed as completed or habitual, they are followed by the indicative. Of course, if there is no change of subject involved and a preposition is available, typically the preposition is used with an infinitive. So when the adverb-clause indicates time, it can be termed as Adverb Clause of Time.
These clauses begin with conjunctions such as...
Whenever, While, After, Before, Since, When, As, As soon as, Till, According as
• When I command this ship, there will be good discipline. • He came after night had fallen.
• After the law was passed, this type of crime ceased.
• Do it before you forget.
• Before you go, bring me some water.
• I have not been well, since I returned from New York.
• There was silence as the leader spoke.
• As he came into the room, all rose to their foot.
• The Doctor always comes whenever he is sent for.
• They were commanded to wait till the signal was give.
Adverb Clause of Cause indicates the cause for which the action of the verb is taken. It describes effects or unintended outcomes. Conjunctions used: because, as, since and now that.
Because he likes his master, he helped his master.
In this sentence, why he helped his master has been answered by the Adverb-Clause ‘because...