In technical and scientific English, there is a tendency to shorten certain kinds of passive constructions. Three such kinds of sentences are commonly used in procedural descriptions. The first type is a compound sentence with two identical subjects and two or more verbs in the passive. To shorten this kind of sentence, omit the subject and the be auxiliary in the second part of the sentence.
The second type of sentence is also compound, but in this case there are two different subjects, each with different verbs in the passive voice. To shorten this kind of sentence, omit the be auxiliary before the second verb.
The third type of sentence has a which clause containing a passive verb form. In this case, you can shorten the clause by dropping the conjunction which and the be auxiliary.
CHOOSING VERB TENSE AND VOICE IN DESCRIBING MATERIALS
There are also some grammatical conventions you should know in order to describe materials clearly in your report. These conventions mainly involve choosing the correct verb tense and voice.
