English Writting Handbook

Archiwum

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the real action in the sentence; the subject is then either receiving the action or preferably performing it. In the first
sample sentence, identify the action. From among the several words of action (indication, reduction, operation, is
shown, presented), indication seems most important. Two revisions come to mind when indicate becomes the
main verb:
Asymmetric throat area reduction between the upper and lower throats of this nozzle during
reverse thrust operation is probably indicated by the jet lift coefficients presented in figure 28.
The jet lift coefficients presented in figure 28 indicate a probable asyrnmetric throat area reduction
between the upper and lower throats of this nozzle during reverse thrust operation.
Which sounds best? The second revision, with an active verb close to its subject, is certainly easier to read. Out
of context, it is preferable. Context affects the choice of subject. For good transition from one sentence to
another, the subject of a sentence should relate to the previous sentence.
Now consider the second sample sentence, containing the indirect construction. The expletive there forces the true
action of the sentence, indicating, into a participial construction. Making indicate the main verb results in
At NPR
decrease in the effective throat area for the nozzles.
Another indirect construction involves the pronoun it:
It appears that grain refining improved the toughness of
Indirect
maraging steels.
Grain refining seemed to improve the toughness of
Better
maraging steels.
It is obvious that a blackbody laser is feasible as a space
Indirect
power system.
Obviously a blackbody laser is feasible as a space power
Better
system.
As with any valid grammatical construction, indirect constructions sometimes serve a function, but many
grammar and writing books criticize them as being wordy (see section 2.4.1) and unnecessary. Rowland (1962)
states that "expletives serve only to mark time until the true grammatical subject appears." In Tichy and
Fourdrinier's (1988) opinion, as well as in Rowland's, indirect constructions can be ambiguous. Such idioms as
"it is known" or "it is believed" indicate general knowledge or belief:
It is believed that this is a nozzle-aspect-ratio effect.
In most technical writing, these constructions refer to the author's belief or knowledge. Perhaps a personal
pronoun is appropriate (see section 1.3.2):
We believe that this back pressure increase is a nozzle-aspect-ratio effect.
Note the change in the subordinate clause of this sentence. Demonstrative pronouns (this, these, that, or those
used as nouns) with "broad reference" (Ebbitt and Ebbitt 1982) can be undesirable and ungrammatical when their
antecedent is not clear (see section 1.3.1):
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Chapter 2. Sentence Structure
Mass flow rate increased in the cove. This resulted in
Poor
increased cove gas temperature.
The increasing mass flow rate in the cove increased cove
Better
gas temperature.
Please do not insert stock abstract words such as result, effect, or apparatus after every demonstrative pronoun.
Remember that the subject of a sentence (or clause) should be clear and concrete and should relate to previous
ideas.
2.2.2. Make Verbs Vigorous
The only words capable of expressing action are verbs and their derivatives. Invigorating verbs will make writing
more concise and easier to read. In the following phrases, the action of the verb reduce is progressively
deemphasized:
Active voice If we reduce drag, . . .
Passive voice If drag is reduced, ...
Verbal With reduced drag, ...
Verb-derived noun With reduction of drag, . . .
Weak verbs
One of the most common causes of weak verbs has already been discussed; when the real verb of a sentence
becomes the subject, a weaker verb must be substituted:
A comparison of lift coefficients for the two configurations
Poor
is presented in table II.
Lift coefficients for the two configurations are compared in
Better
table II.
The agreement between calculated and experimental heating
Poor
rates was within 30 percent.
Calculated and experimental heating rates agreed to within
Better
30 percent.
Asymmetric throat area reduction between the upper and
Poor
lower throats occurred during reverse thrust operation.
Throat area decreased asymmetrically between the upper
Better
and lower throats during reverse thrust operation.
Another method of weakening verbs is to hedge with such words as might, may, seem to, appear to, or tend to.
Hedges not only weaken the verb, as they are meant to, but also imply indecision on the part of the author. They
should not be overused (see section 2.4.1).
Active versus passive voice
As discussed in section 1.4.3, writing authorities overwhelmingly prefer active voice to passive voice. However,
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Chapter 2. Sentence Structure
Tichy and Fourdrinier (1988) list five situations when passive voice is appropriate:
" When the actor is unimportant, not known, or not to be mentioned
" When the receiver of the action should be emphasized
" When the sentence is abrupt in active voice
" When variety is needed in an active voice passage
" When a weak imperative is needed
Although the first two items justify much of the passive voice in technical documents, the converse of the fourth
item must also be considered. In our passive voice reports, an occasional active voice sentence is needed for
variety. (Tichy and Fourdrinier 1988 also discuss the importance of sentence variety to good style.) Thus editors [ Pobierz całość w formacie PDF ]

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