For basic passive construction in English, a very special obligatory transformation of the active sentence is required to turn the active subject into the passive subject.
- Thus, a sentence containing an active verb and object makes it possible for the sentence to transform into a passive sentence. Examples;
Armed robbers destroyed the bank vault completely. → Active
The bank vault was destroyed by armed robbers. → Passive
The verb ‘destroyed’ used in the above sentences is transitive, making the passive construction possible.
2. The second ingredient of true passive construction is that there must be some sense of correspondence between the active and the passive, as in the following sentences:
Every Friday, she serves/eats fried rice. → Active voice/present tense
Fried rice is served/eaten (by her). → Passive voice/present tense
Yesterday, she served/ate fried rice. → Active/past tense
Yesterday, fried rice was served/eaten (by her). → Passive/past tense
The tense correspondence should also be reflected in the modals, as in the following sentences:
She could type the whole document. → Active
The whole document could be typed (by her). → Passive
The forms of the auxiliary verb ‘be’ in English: be, am, is, are, was, were, being, and been are followed by the past participle form to form passive sentences. Consider the following sentences:
1a.She eats one egg daily. → Active
1b. One egg is eaten daily (by her). → Passive
2a.He tells me to be prayerful. → Active
2b. I am told to be prayerful. → Passive
3a. We obey our teachers. → Active
3b.Our teachers are obeyed. → Passive
4a. We invited the king. → Active
4b. The king was invited. → Passive
If you study the above examples very carefully, you will notice that the grammatical subject in the passive form determines the form of ‘be’ used in the sentences. For ‘be’ to be used in the passive form, the active form would have modal auxiliary verbs: ‘may/might,’ ‘can/could,’ ‘shall/should,’ ‘will/would,’ and ‘must.’ ‘Being’ is used in the passive only if the main verb in the active voice is in the progressive aspect, i.e., if it attracts the ‘-ing’ participle. Finally, ‘Been’ is used in the passive form only if the active voice contains ‘has’, ‘have’, or ‘had’.
3. Another basic ingredient for passive correspondence of the modal auxiliary verb in both the active and passive constructions is the potential correspondence of the modal auxiliary verbs. Some modal auxiliary verbs are: ‘will’/’would’, ‘may/might’, ‘can/could’, ‘shall/should’, and ‘must’. So, consider the correspondence of the verb forms across the voice forms:
| ACTIVE | PASSIVE |
| I will/may take your pen. | Your pen will be/may be taken. |
| I would/might take your pen. | Your pen would be/might be taken. |
| I can/could take your pen. | Your pen can be/could be taken. |
| I shall/should take your pen. | Your pen shall be/should be taken. |
| He must not take your pen. | Your pen must not be taken. |
You need to understand from the above that there is a correspondence of modals between the active and the passive. In other words, irrespective of the transformation from active to passive, ‘will’ in the active takes, ‘will’ in the passive, ‘would’ in the active takes, ‘would’ in the passive, and so on.
As mentioned above, since the object of the active must become the subject of the passive, then sentences without a direct object cannot transform into passive. Generally, intransitive verbs (verbs that cannot take an object) and linking (equational) verbs, e.g., appear, become, feel, remain, seem, look, sound, etc., cannot be used to show passive constructions.
Samples of Texts in the Passive Form
Although passive can be found in all kinds of writing, research has shown that it is more commonly used in the language of science and technology. If you are a student of science or engineering/technology, you should expect to encounter more passive sentences in your readings. You may then begin to ask yourself why the passive is more prominent in science and technology writing than any other form of writing. Below are some sample texts.
Concept of Energy Conversion
Each of these forms of energy […] can be converted from one form to another […]. Usually, energy conversion is like going in a circle. For example, potential energy in a piece of metal released at a certain height will hit the floor. The potential energy is converted to kinetic energy (and is), then heat, and (is then) finally (converted) back to potential energy.
(cf. Ogunniyi, M.B. et al.(2010) Basic Science and Technology for Primary Schools. Ibadan: Macmillan Nigeria Publishers. p.120)
Extraction of iron and manufacture of steel
Iron and steel have variously been described as the backbone of industrialization in any nation. In Nigeria, the development of the iron and steel industry since 1970 has been accorded the utmost priority. Iron and steel are needed to construct our houses, bridges, and heavy machinery.
Extraction of iron: The Blast Furnace Method
The main iron ore is magnetite (Fe₃O₄). The reduction of the magnetite is carried out in a blast furnace. The magnetite, limestone, and coke are fed into the furnace from the top. A blast of hot air 800°C is blown into the furnace through the tuyeres located towards the furnace.(cf. Science Teachers Association of Nigeria, 2008 Nigerian Basic Science Project JSS 3. Ibadan: HEBN Publishers Plc. p. 65).
Interesting Experiments
Other interesting experiments showed the existence of yet another fundamental particle. When small holes were bored in the cathode of the discharge tube, cathode rays were produced due to applying a high voltage, and other rays were seen. These rays traveled in the opposite direction to the cathode rays and were deflected in the opposite direction by electrical and magnetic fields. This meant that the rays consisted of positively charged particles and were given the name positive rays. (cf. Afolayan, S. A. 1980 O’ Level Chemistry for West Africa. London: Macmillan Education Limited. p. 58).
Comments on the Above Texts
Looking at these extracts closely, you will see that all the verbal elements in the passive form have been identified for you. Can you locate their subjects? They are the agentless passives. For instance, in sentence 1 of Text 3, can you tell us who or what performed the ‘other interesting experiments’? This shows that agentless passives are much more common in scientific and technical writings than agented passives. Secondly, can you notice the structure of the underlined predicates? They all consist of the appropriate forms of the auxiliary verb ‘be’ plus the past participle form of the lexical verb, e.g., is carried, are fed, were performed, were bored, were produced, etc. However, notice that while some are in the present tense, others are in the past tense. Finally, can you suggest why these scientific writers may have preferred using passive sentences instead of active sentences in these three texts?
Conclusion
You should realize by now that passive construction is an alternative to active construction. Therefore, using a passive form is more a matter of choice and style than being arbitrary. In other words, the writer has a choice open to him/her according to the context or situation within which he/she could interact or inform his/her reader/audience to present the best meaning he/she desires.It is also important to show that the retention or otherwise of the by-agent in the passive is not arbitrary; rather, it could lead to a change of meaning, even if slightly. Ballard (1979) cites in his review of Halliday’s Language as a Social Semiotic the instance, among others, of the following sentences:
- The superintendent did not fire John.
b. John was not fired by the superintendent.
c. John was not fired.
He interprets sentences (a) and (c) to mean that in normal non-contrastive reading, John is still gainfully employed, while in (b), John is no longer employed. Yet, sentences (b) and (c) are both supposed to be passive constructions of sentence (a), and they are! However, this change in scope and/or meaning cannot be regarded as irrelevant simply by deleting or not deleting the agentive adjunct in sentences (b) and (c). It is a choice the writer has to make deliberately. Thus, the choice between the active and the passive should depend on which one enables us to present more exactly, clearly, and beautifully the aspect of reality we wish to represent. It should depend on which one refines our thoughts more satisfactorily.
