Bài giảng chuyên đề 3 - Sentence structure

ntroductory elements, nonessential elements, items in a series, independent adjectives, contrasting expressions, omitted words, and quotations.
Apply commas correctly with compound sentences, questions within statements sentences, and special cases.
Use semicolons to connect independent clauses, items in a series, and transitional expressions.
Use colons to connect independent clauses that function as a unit, items in a series, items in a list, quotations, and special expressions.
Introduction
Commas, semicolons, and colons pose problems for many writers. In fact, these marks, the comma in particular, are some of the most misused in the English language. The guilines you are about to learn will show you how to distinguish when to pause and separate word groups with commas, when to connect related ideas with semicolons,and when to illustrate and introduce ideas with colons. You will also learn the special uses of these marks, so you can communicate a variety of ideas clearly and completely.
Terms: contrasting expressions, independent adjectives, nonessential elements, parenthetical expressions, items in a series.
COMMAS
If we can imagine sentences as streets, punctuation would be their road signs. Commas, semicolons, and colons signal a pause because a change in thought is to follow. They are internal punctuation marks, meaning that you find them within sentences.
 Commas are the most widely used of these three signs. They are used with introductory elements, nonessential expressions, essential phrases and clauses after the main clause, items in a series, compound sentences, independent adjectives before a noun, contrasting expressionsm statement and question sentences, omitted words, quotations, special cases, and additional uses.
( Writers on writing: Find your own voice. Say the things you have to say the way you say them, not the way someone’s just said them before you.)
Introductory Words, Phrases, and Clauses
 Introductory Words
Use a comma after an introductory word. Such words are used to emphasize the literal meaning of the sentence.
Examples:
- Why, this copy machine has never run so slowly!
- Now, when can we expect the new accelerated graphic card?
Introductory Phrases and Clauses
Use a comma after an introductory element that contains a verb.
Example: To be sure, we should refer to the NEC specifications.
The comma keeps the reader from confusing to be sure with the main verb of the sentence, should refer.
 Except for adverb clauses and phrases containing verb forms, the comma may be omitted after short introductory elements if no confusion would result. The rule is that a comma may be omitted after introductory elements of four words or less. However, when a verbal phrase functions as the subject omit the comma.
Examples:
- At 8 A.M. we will begin replacing the two existing file servers.
- Our advertizing helped the sales significantly.
Introductory Prepositional Phrases in a Series
Use a comma after a series of short introductory prepositional phrases.
Examples:
- In the storage room on the shelf by the desk, you will find two 10-gig hard drives.
- Across the road over the hill by the tall willow, a lone technician tests water quality.
Nonessential Expressions
Nonessential words, phrases, and clauses are elements that add emphasis to sentences. Direct address, nonessential appositives, and parenthetical expressions are examples of nonessential information; that is, they are not necessary to the grammatical completeness of the sentence, nor do they add information that is necessary to its meaning. You use them to add interest.
Direct Address
Direct address is actually “talking” to ( referring) one or more people. 
Examlpes:
- I wanted to tell you, Steve, that your job performance has been exemplary.
- Valued customers, it’s the best time to install solar heating.
- It’s the best time to install the solar heating, valued customers.
Direct address is used largely to reinforce your reader’s attention as well as personalize it. Direct address, therefore, is not essential to the meaning of the sentence and should be set off with commas.
Appositives
An appositive is a word or group of words that defines, renames, or identifies a preceding noun or pronoun. Use commas to set off appositives that are not essential to the meaning of the sentence.
Examples:
- My assistant, Amy Hamilton, will explain the consent form to you.
- Mr. Robert, my boss, just gave me a promotion.
However, if the appositive is essential to the meaning of the sentence, do not use comma. In this example, the writer has more than one sister.
Example: My sister Mary will be arriving today from St.Paul.
Do not use commas when the commas would otherwise disrupt the meaning of the sentence. Oftentimes, other punctuation may be required for your meaning.
Examples:
- Mary- our writer- and I are organizing the document.
- Mary, our writer, and I are organizing the document.
( Mary is the writer)
The commas change the appositive into a series construction, suggesting that three people are helping. (See the section “Items in a Series.)
Parenthetical Expressions
A parenthetical expression emphasizes the meaning of a sentence, but it is not essential to its meaning or its grammatical structure. Therefore, it requires commas.
Examples:
- As you can imagine, biomedical work is complex.
- The answer is no, of course.
- Most of the ductwork, however, has been installed.
Essential Phrases and Clauses
Essential phrases and clauses are word groups that are necessary to the meaning of a sentence. Do not use commas to set off phrases and clauses with such essential meanings.
Examples:
- The employee in the storeroom can help you.
- The man who is standing next to the water fountain has a 9.30 appointment.
“ In the storeroom” tells which employee can help, so the information is essential. “ Who is standing next to the water fountain” identifies who has a 9.30 appointment.
 Can you determine if the dependent clause is essential or nonessential in the next example?
Example: Jim Lopez, whom I have known for twenty years, does our R&D.
“ Whom I have known for twenty years” does not add essential meaning or grammatical completeness to the sentence. Be careful to recognize clauses with nonessential meanings, requiring commas.
Phrases and Clauses after the Main Clause
You don’t usually have to place a comma between a main clause and any pharses or dependent clauses that follow. The phrase or dependent clause is typically essential to the meaning of the main clause. The meaning is usually clear without a comma.
Examples:
- We must work together to accomplish this task.
- Kyle studies daily because his associate’s program is very challenging.
However, if the dependent clause that follows the main clause begins with as, as though, or although, a comma is preferable.
Example: He is good at testing new circuits, although his specialty is application.
Also, if a clause is meant to be an afterthought, use a comma before the clause.
Example: Our customers responded in a positive manner to the recall notice, if you can imagine that.
Items in a Series
Use commas to separate items in a series. This method prevents confusion for the reader.
 Words
Examples:
- I am assigning Kyle, Rennee, and David to the Catlin Mills’.
- Amy, Susan, and Karen constitute the quality-control team.
Phrases
 Examples:
- We will install a 4-ton air conditioner, a 4-ton air handle, and a 8-kw heater on the second floor.
- I have a red pickup, a yellow sedan, and a maroon Jeep.
Clauses
 Examples:
- Item 1 costs $3,500, item 2 cost
- I assemble the data, she writes the manual, and he prints the text.
Compound Sentences
Place a comma before a coordinate conjunction that joins each dependent clause.
Examples:
- Jim will draw the construction plans today, so the screw can begin on Monday.
- We recently opened a facility in St. Louis, and our office is sending technical support to service the new location.
If each independent clause has four or fewer words, the comma may be omitted.
Example: Her work was stressful but it was rewarding.
Independent Adjectives before a Noun
Use comma to separate independent adjectives before a noun.
Example: The CAD printout had tiny, dashed lines.
Note in the following examples when to omit the comma before the final adjective ( when it is part of the noun or when one modifier describes another in the phrase.)
Examples:
- He was part of a high-rise construction project.
- The building had steel upper levels.
The final adjective, construction, is closely related to the noun project.
Contrasting Expressions
Use commas to set off contrasting expressions.
Examples:
- I want only one worker, not two, sent to our St. Louis plant.
- The satellite is large, but vulnerable, to meteors.
Statements and Question Sentences
Use comma to set off questions of validation within direct statements.
Examples:
- Susan, you’re not leaving, are you?
- Andy was here, wasn’t he, to install the network cards?
Omitted Words
In some instances, a comma can be used to replaced words that are easily understood from the context of the sentence.
Examples:
- Today we will apply chemicals to the vegetable plots; tomorrow we will apply the chemicals to the flower plots.
- Today we will apply chemicals to the vegetable plots; tomorrow, to the flower plots.	 
Quotations
Use commas to set off direct quotations.
Examples:
- “ I just grew into the field of agricultural research,” said Joe.
- Andy said “ I always maintain a notebook on observations taken in the field.”
Special Cases
Place a comma between words that might otherwise be confusing.
Examples:
- Whatever you choose to do, do it now.
- Sshortly after, Leroy and Andy helped each other measure a field.
Additional Uses
Using commas properly in dates and addresses will help you avoid misleading your reader.
Dates
Examples:
-