Compound Sentences with Semicolons

 

Independent clause; independent clause

 

 

Ex. My older brother studies law; my younger brother studies medicine.

Poland was the first Eastern European country to turn away from communism; others soon followed.

 

This kind of compound sentence is possible only when the two independent clauses are closely related in meaning. If they aren’t’ closely related, they should be written as two simple sentences, each ending with a period.

 

Practice VIII Write three compound sentences of your own on the topic of your research, using a semicolon to join the independent clauses.

Practice IX Use what you have learned about forming compound sentences to improve the following mini-essay, which contains many short, simple sentences. Combine sentences wherever possible. Try to use each of the three methods at least once. There are many possible ways.

 

Robots

A robot is a mechanical device that can perform boring, dangerous, and difficult tasks. First of all, robots can perform repetitive tasks without becoming tired or bored. They are used in automobile factories to weld and paint. Robots can also function in hostile environments. They are useful for exploring the ocean bottom as well as deep outer space. Finally, robots can perform tasks requiring pinpoint accuracy. In the operating room, robotic equipment can assist the surgeon. For instance, a robot can kill a brain tumor. It can operate on a fetus with great precision.

The field of artificial intelligence is giving robots a limited ability to think and to make decisions. However, robots cannot think conceptually. Robots cannot function independently. Humans have to program them. They are useless. Therefore, humans should not worry that robots will take over the world – at least not yet.

 

4. A complex sentence contains one independent clause and one (or more) dependent clause(s). A bit of theory! In a complex sentence, one idea is generally more important that the other one. The more important idea is placed in the independent clause, and the less important idea is placed in the dependent clause.

There are three kinds of dependent clauses: adverb, adjective, and noun.

4.1 Adverb clauses

A dependent adverb clause begins with an adverbial subordinator such as when, while, because, although, if, so that, etc.

 

Ex. 1 Alhough women in the United States could own property, they could not vote until 1920.

2.In the United States, women could not vote until 1920 although they could own property.

 

Notice! There are two possible positions for an adverb clause: before or after the independent clause. If it comes before the independent clause, it is followed by a comma (sentence 1). If it comes after the independent clause, NO comma is used (sentence 2)

 

A dependent adjective clause (relative) begins with a relative pronoun such as who, whom, which, whose, or that or with a relative adverb such as where or when. An adjective clause functions as an adjective; that is, it modifies a noun or pronoun in the independent clause.

 

4.3 Punctuation of Relative Clauses

Relative clauses are either restrictive (necessary) or nonrestrictive (unnecessary). Do not use commas with restrictive clauses.

 

Ex. The professor who teaches my biology class won a Nobel Prize two years ago. (Which professor won a Nobel prize two years ago? The clause who teaches my biology class is necessary to identify the professor.)

He won the prize for research that might lead to a cure for AIDS. (For which research did he win the prize? We need the clause that might lead to a cure for AIDS to tell us.)

 

A nonrestrictive clause is not necessary to identify something or someone; it merely gives the reader some extra information. Because it can be omitted without loss of meaning, separate it from the rest of the sentence with commas.

 

Professor Jones, who teaches my biology class, won a Nobel Prize twp years ago. (The person who won a Nobel Prize is identified by his name, so the clause who teaches my biology class is extra, unnecessary information about Professor Jones. If it were omitted, we would still know which person won the Nobel Prize.)

He won the prize for his research into the structure of T-cells, which might lead to a cure for AIDS.

 

Practice I Underline the relative clause or clauses in each sentence. Add commas to the nonrestrictive clauses.

1. The sun which in forty minutes can produce enough solar energy to meet humankind’s needs for a year is one of Earth’s potential sources of power.

2. According to an article that appeared in Time magazine we are at the beginning of a medical computer revolution.

3. A medical computer is a machine that analyze the results of laboratory tests and electrocardiograms.

4. Laser beams which are useful in both medicine and industry were first predicted in science fiction stories seventy-five years ago.

5. Physicians who need patient symptoms into the computer receive a list of diseases that fit the symptoms of their patients.

6. The public is highly critical of the tobacco industry whose profits have been increasing in spite of the health risks of smoking.

7. Carbohydrates which are composed of carbon, hydrogen, and oxygen are organic compounds.

8. X-ray machines are gradually being replaced by machines that can provide clearer, more detailed images of the human body, its tissues, and its organs.

9. X-ray machines are gradually being replaced by CAT scanners and MRI devices which can provide clearer, more detailed images of the human body, its tissues, and its organs.

10. The country that has the highest per capita income is not the United States which is in third place.

 

Relative Pronouns

who	refers to humans	subject in its own clause	restrictive or nonrestrictive	The professor who teaches my biology class won a Nobel Prize two years ago. Professor Jones, who teaches my biology class, won a Nobel Prize two years ago.
whom	refers to humans	subject in its own clause	restrictive or nonrestrictive	She loaned her car to someone whom she didn’t know. Professor Jones, whom I have for biology, won a Nobel Prize two years ago.
whose	refers to humans, nonhumans, and things; shows possession	subject or object in its own clause	restrictive or nonrestrictive	I studied algebra from a professor whose name I have forgotten. Apple Computer, whose Macintosh computer changed computing, was started by two men working in a garage.
which	refers to nonhumans and things	subject or object in its own clause	nonrestrictive only	She teaches biology, which is my favorite subject. Her husband teaches algebra, which I enjoy the least.
that	refers to nonhumans and things; informally, refers to humans	subject or object in its own clause; if that is an object, it may be omitted	restrictive only	The class that meets in the next room is very noisy. The subject that I enjoy the least is algebra. The subject I enjoy the least is algebra. The salesman that sold me my car was fired. (informal)

Relative Adverbs

When	Refers to a time		restrictive or nonrestrictive	I work full time on days when I don’t have classes. I didn’t work last week, when I had my final exams.
where	Refers to a place		restrictive or nonrestrictive	She has never returned to the city where she was born. First City Bank, where I have a checking account, was robbed last week

 

You can use relative clauses to improve your writing style. As you, writing that contains subordinate structures is more sophisticated that writing that contains mostly simple and compound sentences. Relative clauses are one of the ways to subordinate. (However, take care not to use too many relative clauses. A paragraph or essay that is filled with too many who’s and which’s not good either.)

There four kinds of errors in relative clauses:

1. Incorrect relative pronoun was chosen.

Ex. I telephoned the student which wallet I found in the parking lot. (Which is not correct, it must be replaced by whose.)

2.Verb and antecedent don’t agree.

Ex. People who lives in earthquake zones need earthquake insurance. (people live)

3.Nouns or pronouns are repeated.

Ex. My friend whom I loaned my car to him returned it with several dents.

4.Commas should be added or deleted.

Ex. Mobile phones, which always seem to beep at inappropriate times, should be turned off during concerts, lecturers, and naps.

Practice II Edit the following essay for errors in relative clauses. You should make 17 changes.

El Nino

Recently, scientists have begun studying an ocean event who is the cause of drastic changes in weather around the world. This event is an increase in the temperature of the Pacific Ocean that appear around Christmas off the coast of Peru. Hence, the Peruvian fishermen whom first noticed it named it El Nino whose its name means “the Christ child” in Spanish. The cause of this rise in ocean temperature are unknown, but its effects are obvious and devastating.

One of El Nino’s far-reaching effects is that it threatens Peru’s vital anchovy harvest, which could mean higher prices for food. The warm water of El Nino keeps the nutrient-rich cold water which provides anchovies with food down at the bottom of the ocean. Anchovies are the primary source of fish meal which is the main ingredient in livestock and chicken feed. In addition, guano from birds who feed off the anchovies is a major source of fertilizer for farmers. As a result of decreasing supplies of anchovies and guano, the price of chicken fed, livestock feed, and fertilizer rises. This causes farmers who they must pay more for feed and fertilizer, to charge more for the food that they produces. The price of eggs, meat, and even bread has scared as a result of El Ninos in past years.

El Nino has other global effects. It can cause heavy rains, floods, and mudslides along the coasts of North and South America and droughts in other parts of the world. In the 1982-83 El Nino, West Africa suffered a terrible drought which caused crop failures and food shortages. Lack of rain also created problems for Indonesia whose forests burned for months during the 1997-98 El Nino. Winds spread smoke from these fires as far north as Malaysia and Singapore, resulting in choking smog, that closed schools and caused pedestrians to don masks.

Indeed, El Nino is an unpredictable and uncontrollable phenomenon of nature, that we need to study it and understand it in order to prepare for and perhaps lessen its devastating effects in the future.

 

5. A compound-complex sentence is a combination of two or more independent clauses and one (or more) dependent clauses. Many combinations are possible, and their punctuation requires careful attention.

 

1. I wanted to travel after I graduated from college; however, I had to go to work immediately.

2. After I graduated from college, I wanted to travel, but I had to go to work immediately.

3. I wanted to travel after I graduated from college, but I had to go to work immediately because I had to support my family.

4. I couldn’t decide where I should work or what I should do, so I did nothing.

 

You punctuate the compound part of a compound-complex sentence like a compound sentence; that is, use a semicolon/comma combination (sentence 1), or put a comma before a coordinator joining two clauses (sentence 2,3, and 4).

You punctuate the complex part like a complex sentence. With adverb clauses, put a comma after s dependent clause (sentence 2) but not before them (sentence 3). With noun clauses no commas (sentence 4).