Giáo án tiếng Anh 12 - Sentence structure

onstruction 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:
- On September 5 the satellite will be ten years old.
- On September 5, 20XX, the satellite will be ten years old.
- On Friday, September 5, the satellite will be ten years old.
- On Friday, September 5, 20XX, the satellite will be ten years old.
- In September 20XX the satellite will be ten years old.
Addresses
Examples:
- I will be working at Battle Research Institute, 1002 Cornwall, Yukon, OK 73099-2612.
- I hope to be in Kansas City, Missouri, by night.
Semicolons
Semicolons are signs that signal longer pauses than commas. They are used to join independent clauses that have closely related ideas, items in a series when the items themselves already contain commas, and with certain transitional expressions.
Independent clauses
Use a semicolon in place of a coordinate conjunction when one or more independent clauses expand on an idea expressed in a previous independent clause. Note: Be careful when deciding whether to use a semicolon or to divide the sentences with a period ( and a capital letter). Use a semicolon only when a period would create an abrupt division between the ideas.
Examples:
- We are providing performance data for corn, we hope you have the figures for soybeans.
- I can’t give you an answer now; I need to review the data.
Use a semicolon with a coordinate conjunction to connect independent clauses if the clauses contains enough commas that could confuse the reader as to where the second clause begins.
Example: Andy, our technician, is competent, motivated, and qualified; and he, I believe, is due for a promotion.
Use a semicolon between independent clauses when the transitional expressions is a conjuctive adverb.
Examples:
- Karen expressed concern about her exam; nevertheless, she received an excellent grade.
- I would love to go to the party; however, we have a “ systems down” situation.
Items in a Series 
A semicolon may be used to connect a series of three or more independent clauses with closely related ideas.
Examples: I should receive the blueprints on Friday; Charlie Roberts can review them on Monday; and I can prepare the company’s base bid on Tuesday.
If independent clauses in a series are very short, use commas to separate the items.
 Use a semicolon between items in a series when the items themselves contain commas.
Example: We have offices in Louisville, Kentucky; Springfield, Missouri; Omaha, Nebraska; and Denvor, Colorado.
Transitional Expressions
Use a semicolon before such transitional expressions as namely, that is, and for instance when they introduce a series of examples containing commas.
Example: Most of us are aware of the major contributors to poor health; namely, stress, poor diet, and lack of exercise.
Other Transitional Expressions
 for example (e.g.) 
 that is
Use a semicolon before such transitional expressions and a comma after them when these expressions separate two independent clauses.
Example: The builders and the electricians are both scheduled to begin on July 12; that is, we have an oversight.
Colons
Colon signal longer pauses than commas and semicolons. They are used to connect an initial sentence to a sentence that illustrates or completes the first; after a sentence that introduces a series of items; and after a sentence that introduces a quote.
When two sentences function as a unit, with the second illustrating or completing the first, separate them with a colon.
Example: Andy has determined the solution to the slow response time in the accounting department’s network system: Large disk drives need to be installed in three computers.
Items in a series
 Use a colon after a sentence that introduces a series of items in the running text. Direct introductory statements usually include one of the following words: following, as follow, are these, and thus.
Example: The following people need to turn in their vacation request forms: Patricia, Keisha, Leroy, and Joanne.
An introductory sentence may not contain one of the words previously mentioned; however, use a colon if that sentence strongly suggests that supplementary material is to follow.
Example: Kyle is separate to draft a job-bid proposal: He has surveyed the premises, determined the labor time, and priced the necessary materials.
Items in a list
Use a colon after a sentence that introduces a vertical list.
Example:
 The five-point maintenance service for $29.95 includes the following:
Change furnace filters
Check all burners
Check flue
Check fan motors in AC and furnace
Clean outside AC units
Quotations
Use a colon after a complete sentence that introduces a quotation.
Example: The governor sought to inspire all young technicians present: “ Minority businesses contribute substantially to Ohio’s economic vitality.”
Additional Uses
Colons are also used with time expressions, salutations, titles, subtitles, and ratio expressions.
Time expressions: I will see you at 8:00 A.M.
Salutations: Dear Ms. McClain:
Titles with Subtitles: The Freshman Experience: A Survival Guide
Ratio Expressions: At our hospital, pharmacy technicians outnumber pharmacist, 2:1.
Rules Summary for commas, Semicolons, and Colons
Before you begin the worksheets for this chapter, you may want to review the following rules for commas, semicolons, and colons, as well as their examples within the text.
Commas
- Use a comma to separate an introductory word that emphasize the meaning of the sentence.
- Use a comma after an introductory element that contains a verb form. A comma may be omitted after short introductory elements that do not contain a verb form.
- Use a comma after a series of short introductory prepositional phrases.
- Set off items of direct address with commas.
- Use commas to set off appositives that are not essential to the meaning of the sentence.
- Do not use commas to set off appositives that are essential to the meaning of the sentence.
- Use commas to set off phrases and clauses that are not essential to the meaning of the sentence. Do not use commas to set off phrases and clauses that are essential to the meaning of the sentence.
- In general, do not place a comma between a main clause and any phrases or dependent clauses that follow. However, if a dependent clause following a main clause begins with as, as though, or though, a comma is preferable.
- Phrases and clauses that follow the main clause but do not affect the meaning of the sentence should be set off with commas.
- Use commas to separate words, phrases, or short clauses in a series.
- Place a comma before a coordinate conjunction that joins independent clauses. The commas may be omitted if each dependent clause has fou or fewer words. 
- Use a comma to separate independent adjectives before a noun. Omit the comma before the final adjective when it is a part of the noun or when one modifier describes another in the phrase.
- Use a comma to set off contrasting expressions.
- Use commas with questions of validation within direct statements.
- In some instances, a comma may be used to replace words that are easily understood from the context of the sentence.
- Use commas to set off direct quotations.
- Place a comma between elements or repeated words that might otherwise be confusing.
- Use commas with dates that contain more than two items in their expressions. Use commas in addresses after each item but a state abbreviation and zip code.
Semicolons
- Use a semicolon in place of a coordinate conjunction when one or more independent clauses expand on an idea expressed in a previous independent clause.
- Use a semicolon with a coordinate conjunction to connect independent clauses if the clauses contain enough commas that could confuse the reader as to where the second clause begins.
- Use a semicolon between independent clauses when the transitional expression is a conjunctive adverb.
- A semicolon may be used to separate a series in three or more independent clauses. However, if independent clauses are very short, use commas to separate the items.
- Use a semicolon between items in a series when the items themselves contain commas.
- Use a semicolon before transitional expressions such as namely, that is, and for instance when they introduce as series of examples containing commas. 
- Use a semicolon before these expressions and a comma following them when they separate independent clauses.
Colons
- When two sentences function as a unit, with the second illustrating or completing the first, separate them with a colon.
- Use a colon after a sentenc