Grammatical Features of EST: The Passive Voice in Impersonal Scientific Statements


EST differs from ordinary English in the use of tense, voice, mood，word order and sentence construction.
It is assumed that the readers of EST have already had a good deal of instruction in grammar. Therefore, the principal purpose here is to show readers how to comprehend the grammar which appears most commonly in EST writings.

Probably one-third of the verbs in EST writings are in the passive voice. The tense of these passive verbs is the Present Simple or the verb is used with modals. Scientists and engineers use the passive much more frequently than most other writers.

Why Does the Passive Most Frequently Occur in EST
1. It Is Clearer in Meaning,
Since scientists are more interested in action and facts than the actors, many references to people are unnecessary and confusing. Look at this sentence；
“People heat the gas carefully."
Who are these people? The writer? The writer and his readers? All educated people? Everybody?
All these confusing questions can be avoided by using the passive；
“The gas is carefully heated. ”

2. It Allows Scientists to Introduce the Most Important Information at the Beginning.
As we all know, the subject is a very important part of the sentence. In passive sentences， the subject which contains a lot of information, comes first and catches immediately the reader's attention. Example：
Electrons closer to the nucleus are held more tightly than those in the outer orbits,

3. Passive Sentences Are Usually Shorter and More Concise than Active Ones.
Compare these two sentences；
"Mathematics is used in many different fields. ”
“People use mathematics in many different fields. ”
It may not be difficult to find that the first sentence is shorter and more concise than the second one.

The Function of the Passive
1. Stating Rules or General Principles. Examples ：
a. The pressure that makes electrons flow along wires is called“voltage”.
b. All matter is made up of atoms.
c. Many car engines are cooled by water.
d. The door was opened with a key.