adverbial clause

Adverbial clause

The first page focuses on adverb clauses which are often called "time clauses" in English grammar books and follow specific patterns. Take a look at the chart below to study the various usage of different time expressions.
Punctuation
When an adverb clause begins the sentence use a comma to separate the two clauses. Example: As soon as he arrives, we will have some lunch.. When the adverb clause finishes the sentence there is no need for a comma. Example: He gave me a call when he arrived in town.
Adverb Clauses with Time
When
• He was talking on the phone when I arrived.
• When she called, he had already eaten lunch.
• I washed the dishes when my daughter fell asleep.
• We'll go to lunch when you come to visit.
'When' means 'at that moment, at that time, etc.'. Notice the different tenses used in relationship to the clause beginning with when. It is important to remember that 'when' takes either the simple past OR the present - the dependent clause changes tense in relation to the 'when' clause.
Before
• We will finish before he arrives.
• She (had) left before I telephoned.
'Before' means 'before that moment'. It is important to remember that 'before' takes either the simple past OR the present.
After
• We will finish after he comes.
• She ate after I (had) left.
'After' means 'after that moment'. It is important to remember that 'after' takes the present for future events and the past OR past perfect for past events.
While, as
• She began cooking while I was finishing my homework.
• As I was finishing my homework, she began cooking.
'While' and 'as' mean 'during that time'. 'While' and 'as' are both usually used with the past continuous because the meaning of 'during that time' which indicates an action in progess.
By the time
• By the time he finished, I had cooked dinner.
• We will have finished our homework by the time they arrive.
'By the time' expresses the idea that one event has been completed before another. It is important to notice the use of the past perfect for past events and future perfect for future events in the main clause. This is because of the idea of something happening up to another point in time.
Until, till
• We waited until he finished his homework.
• I'll wait till you finish.
'Until' and 'till' express 'up to that time'. We use either the simple present or simple past with 'until' and 'till'. 'Till' is usually only used in spoken English.
Since
• I have played tennis since I was a young boy.
• They have worked here since 1987.
'Since' means 'from that time'. We use the present perfect (continuous) with 'since'. 'Since' can also be used with a specific point in time.
As soon as
• He will let us know as soon as he decides (or as soon as he has decided).
• As soon as I hear from Tom, I will give you a telephone call.
'As soon as' means 'when something happens - immediately afterwards'. 'As soon as' is very similar to 'when' it emphasizes that the event will occur immediately after the other. We usually use the simple present for future events, although present perfect can also be used.
Whenever, every time
• Whenever he comes, we go to have lunch at "Dick's".
• We take a hike every time he visits.
'Whenever' and 'every time' mean 'each time something happens'. We use the simple present (or the simple past in the past) because 'whenever' and 'every time' express habitual action.
The first, second, third, fourth etc., next, last time
• The first time I went to New York, I was intimidated by the city.
• I saw Jack the last time I went to San Francisco.
• The second time I played tennis, I began to have fun.
The first, second, third, fourth etc., next, last time means 'that specific time'. We can use these forms to be more specific about which time of a number of times something happened.


Sumber : http://esl.about.com/od/grammaradvanced/a/adverb_clauses.htm