Active vs Passive sentence grammar

Review of passive sentence structure
http://owl.english.purdue.edu/owl/resource/539/05/


 

Connecting Clauses
 -Understanding Coordination
Coordination links equal ideas

Therefore, do not use “So,” in the beginning of a sentence in research writing. The purpose of a coordinator is to join two main clauses. The word “So,” at the beginning of a sentence may be used in casual writing and dialogue, but not in engineering writing.

Although you may find some examples of sentences beginning with “and” in the beginning of a sentence, it is quite rare in research writing, and should only be used for emphasis. Generally avoid using “But” at the beginning of a sentence in engineering writing. It is a more casual expression. Use “However,” instead.

Another important point that helps to make the logic of a sentence clearer is putting a comma after a coordinator that joins two main clauses. In the following examples, there is a grammatical difference between the two uses of “and” in this sentence. See how the comma clarifies the structure of the sentence.

X: The president will give out new grants for innovative research proposals and the Ministry of Science and Technology will select the recipients of the grants early next year.

CORRECT: The president will give out new grants for innovative research proposals, and the Ministry of Science and Technology will select the recipients of the grants early next year.

In sentences that are short people tend to omit the comma, however. In addition, if the subject of both sentences is the same we tend not to repeat the subject and we don’t need the comma.

EXAMPLE
I had a cup of coffee and read the newspaper.

TIP
Each sentence should have one main idea. Using AND as a coordinator twice may make a sentence too long and the relationship between the ideas may start to become unclear. Don’t use AND twice in a sentence to join main clauses.

 -Choosing between a coordinator, (semi-)colon, a conjunctive adverb
1) Coordinator vs. correlative conjunction

A coordinator (and, but, so,) establishes a basic relationship between two clauses. The correlative conjunctions (not only X but also Y, both X and Y) put an equal emphasis on both clauses in the sentence and can be an exception to the general rule that there is only one main idea in a sentence. When you want to emphasize both parts of a positive contrast use “not only X but also Y.” For example, compare the difference between these two sentences.

EXAMPLE
A) The proposed method is faster and more accurate than the conventional method.
B) The proposed method is not only faster, but also more accurate than the conventional method.
The first sentence is the “normal” sense of addition. However, if you want to emphasize the results or make an important conclusion then the second structure is more powerful and is a better choice. In the following engineering example, it is clear that the author wants to emphasize both points.

EXAMPLE
This almost perfect growth of each individual pore is a consequence not only of the lithographic pattern but also of the orientation of the silicon single crystal.
Source: Römer et al.: J. AM. CHEM. SOC. 9 Vol. 126, No. 49, 2004 p.16268 ©2004

2) Coordinator vs. semi-colon or conjunctive adverb

The fewer words between clauses, the stronger the connection. If you want to make a stronger connection between two clauses, then choose the semi-colon.

EXAMPLE
1. The experiment was a disaster, so we had to start again.
2. The experiment was a disaster; therefore, we had to start again.
3. The experiment was a disaster; we had to start again.
All of these sentences are possible. Sentence three with the semi-colon makes the strongest connection. It reads more quickly and has a sense of urgency showing a closer connection.

3) Semi-colon; vs. colon:

A colon can also join two main clauses if the information after the colon is a definition or an explanation. A colon, not a semi-colon, also introduces a list.

EXAMPLE
MODIFIED X: They can be divided into three main approaches; frequency, spatial, and temporal.
O: They can be divided into three main approaches: frequency, spatial, and temporal.
Source: Cen and Cosman: IEEE Transactions on multimedia, Vol. 5, No. 1 p. 1 © IEEE 2003
Basically, a colon signals that the information that follows will further explain or define. If the emphasis is on definition, then use a colon. If the emphasis is on connecting two equal ideas, use a semi-colon. You could argue that either a colon or a semi-colon could be possible here.

EXAMPLE
1. The method was not effective; it cost twice as much as existing ones.
2. The method was not effective: it cost twice as much as existing ones.
A semi-colon joins two clauses closely while the colon signals a definition or a list. Here is an authentic example of using a colon to define exactly how a design was modular.

EXAMPLE
Our design is modular: generating the different tiles sets in Figure 1A-D only required replacing strands no. 2 and 4 with versions bearing the desired sticky ends.
Source: Rothemund et al.: J. AM. CHEM. SOC. 9 Vol. 126, No. 50 p.16346 ©2004
Note that this use of a colon to define is not so common and is an advanced writing point.

4) Punctuating a list with a colon.

In a list, some writers put a comma after the second item in a list, but others don’t. Either is correct, but I recommend that you include the second comma to prevent any confusion. If we don’t follow this rule, a few sentences can be confusing to read. Compare these two sentences:

EXAMPLE
X: The new cell phone design has three areas of improvement: cost, color and design and clarity and reception.
CORRECT : The new cell phone design has three areas of improvement: cost, color and design, and clarity and reception. é comma
The sentence is intended to show that the new cell phone design has three areas of improvement: 1. cost, 2. color and design, and 3. clarity and reception. This is clear in the second example but not in the first.

5) Lists of choices

In negative lists or choices, “or” is used rather than “and.”

EXAMPLE
§ Do you want coffee, tea, or coke to drink?
§ Do you want coffee, tea, and coke to drink?
The second sentence would mean that either the person was very thirsty or that they wanted a strange cocktail of three different drinks to wake up and write their engineering article!

6) Sentence structure punctuation errors in coordination

Understanding coordination will also help you avoid one of the most common sentence structure mistakes. Have a look at the following sentence:

EXAMPLE
X: We need to design a new system, it must be three times faster than the current one.
This kind of sentence structure mistake is called a “comma splice.” It is a common sentence structure mistake.
This sentence has two main clauses: 1) We need to design a new system, and 2) it must be three times faster than the one we have now. Therefore, we cannot join the clauses with a comma because it is not one of the options we saw for coordination. A similar error is called a “run-on” sentence.

EXAMPLE
X: We need to design a new system it must be three times faster than the current one.
The solution is to use one of the three ways to join a compound sentence, subordination, or to break it up into two sentences by putting a period between the clauses.
X: We need to design a new system it must be three times faster than the current one.
X: We need to design a new system, it must be three times faster than the current one.

Coordination solutions

CORRECT : We need to design a new system, but it must be three times faster than the current one.
CORRECT : We need to design a new system; it must be three times faster than the current one.
CORRECT : We need to design a new system; however, it must be three times faster than the current one.

Subordination solutions

CORRECT : We need to design a new system that must be three times faster than the current one.

Separate sentences

CORRECT : We need to design a new system. It must be three times faster than the current one.