Real Grammar - Susan Conrad, Douglas Biber 2009

Passives with a By-Phrase
Unit 17 The accident was caused by failure of…

What have you learned from your grammar textbook?

Passive sentences usually do not tell us who the agent is (see Unit 16). When it is important to give the identity of the agent, a by-phrase can be used with the passive verb:

What does the corpus show?

A

A sentence with a by-passive means almost the same thing as a sentence with an active voice verb because both sentences identify the agent. There are three main reasons why we use a by-passive instead of an active voice verb. Many by-passive sentences fit more than one reason.

B

When the agent noun phrase is short, it is usually the subject of an active voice verb:

• They neglected you in the old days.

But if the agent noun phrase is long, we usually express the agent as a by-phrase with a passive verb:

• It was signed by presidents Vinicio Cerezo of Guatemala, Rafael Angel Calderon of Costa Rica, Leonardo Callejas of Honduras, and Violeta Chamorro of Nicaragua.

C

Sentences usually have both “old” information and “new” information. The “old” information refers to people or things that readers are already familiar with. “New” information has not been previously mentioned in the text, and is not widely known. It is usually more important than the “old” information.

In general, writers prefer to put old information as the subject of a sentence, and new information at the end of a sentence. Therefore, if the agent is “new” information, we use a by-passive to put it at the end of the sentence. Thus, “Customs agents” is the new information below:

• Avelino was found innocent of all charges. He had been entrapped by Customs agents.

D

The by-passive is especially common with particular verbs in academic writing. These verbs are special because the by-phrase usually identifies a kind of data or evidence, rather than a human agent:

• The amount of profit in the economy is determined by the amount of surplus value created within it.

In many cases, the by-phrase with these verbs contains a gerund clause:

• Isomerism may be explained by assuming that the atoms are arranged in a definite manner.

Frequency information. Here is a list of passive voice verbs that commonly occur with a non-human by-phrase in academic writing:

• The home range can then be determined by studying the distribution of droppings.

• The causes can be illustrated by considering a simple eccentric wheel model.

• Long term profit expectations are influenced by technological progress.

Activities

1 Notice in context: Read this paragraph from an academic text about diseases in Europe. Circle the passive verbs and underline the agent of each verb.

An account of the spread of cholera through Asia and Europe in the 1830s is given by Walker (1983) and continues to be relevant even today. Today a threat which creates much concern in the United Kingdom is rabies, and it was highlighted by the decision to build a Channel tunnel, directly connecting the UK to the rest of Europe. Rabies was successfully eradicated from the UK at the turn of the century by national efforts; however, the threat of importation of the disease has returned.

2 Analyze discourse: Read these passages from academic writing, complete each one with an active or a by­passive form of the verb in parentheses. Compare your responses with a partner's. Give a reason for each response.

3 Practice writing: The following passages are all grammatically correct; however, the boldfaced sentences need to be rephrased to make them more appropriate for academic writing. Rephrase them by changing active verbs to by-passives and by-passives to active verbs. Write each one on the line provided. Then discuss with a partner why each verb was changed.

1. In West Africa there are four types of vegetation, including the high forest in the south. A wide range of trees suitable for fuel-wood characterizes the forest. In the savannah area there is less vegetation with fewer trees. The limited availability of suitable fuel-wood has contributed to the use of less suitable materials as fuel.

2. The lecture as a form of communication in higher education has been strongly criticized, especially by students. Yet, that lectures do have considerable appeal for students has been shown by a recent investigation. Both students and lecturers said that they felt that lectures gave an opportunity for personal contact.

3. To combat the further spread of disease, general newspaper advertising started during March 1986. Then began a campaign of posters, radio and television. A national telephone information and advice service supported this effort.

4. The study used letters written between Poles in the USA and their families at home in Poland to analyze progress integrating into American culture. A total of 754 letters were purchased and the results were analyzed in groups of family names. Advertising in a Polish-American magazine published in the USA obtained the letters.