Grammar in EAP

Ergative verbs


An ergative verb is a verb that can be either transitive or intransitive. However, when it is intransitive, its subject corresponds to its direct object when transitive. This particularly important when the passive is used. An example is "increase".

Students often misuse words like "increase" and "decrease".

They often write sentences such as:

  • Inflation was increased.
  • Costs were decreased.

when it would be more appropriate to write:

  • Inflation increased.
  • Costs decreased.

This is often an over-correction. They know that academic writing is impersonal and objective and they avoid the active voice and choose the passive, not knowing that there is a more appropriate alternative.

For example:

The annual rate of inflation increased to 1.7% in July, from 1.4% in June, in line with economists' expectations.

Inflation was highest in Greece, at 5.5%, and lowest in Ireland, at -1.2%. Core inflation also increased to 1% from 0.9%, reflecting the impact of VAT increases in Greece, Spain, Portugal and Finland.

(From the Daily Telegraph)


The cost of living in the U.S. unexpectedly decreased in April for the first time in more than a year, reinforcing forecasts that the Federal Reserve will keep interest rates near zero for much of 2010.

(From Bloomberg Business Week)


Compare these two groups of sentences:

  1. The student wrote the report.
  2. The student wrote.
  3. The report was written (by the student).
  4. The report wrote.
  1. The government increased inflation.
  2. The government increased.
  3. Inflation was increased (by the government).
  4. Inflation increased.

In the first group (sentences 1-4) sentences 1-3 have the same meaning. By that I mean that they describe the same real-world situation, although they may have a different focus. In these cases, it is the student that is doing the writing and a report is being produced. Sentence 4 does that mean that. It is a strange sentence because it is the report that is doing the writing!

The second group (sentences 5-8) is different. Sentences 5, 7 & 8 have roughly the same meaning; it is the government (or some other institution) that is causing the increase and it is inflation that is changing. Sentence 6 does not have the same meaning. In sentence 6 it is the government that is changing!

Verbs such as increase are unusual verbs in everyday English but they are very common in academic language. Linguists often call them "ergative verbs" (Lock, 1996, pp. 89-90) or they are referred to as having a "middle" voice as opposed to an "active" or "passive" voice (Halliday, 1967a, pp. 38-46). See Collins COBUILD (1996) for more information and practice.

You could say there were three possibilities:

  • Active voice: The government increased taxes.
  • Passive voice: Taxes were increased by the government.
  • Middle voice: Taxes increased.

In academic writing, when the focus on what is happening, not who is causing it, sentences such as sentence 8 are used very often.They are, however, often combined with other forms:

UK inflation increased from 3% to 3.4% in March and market participants have been increasing their participation in the Index-linked sector.


Here are some more pairs of sentences showing verbs used ergatively:

  • The technician boiled the water. → The water boiled.
  • The subject rang the bell. → The bell rang.
  • The pilot flew the plane. → The plane flew
  • The student broke the machine. → The machine broke
  • The technician varies the volume. → The volume varies.   
  • The government closed the factory. → The factory closed.
  • The tutor enrolled him on a two year course. → He enrolled on a two year course.

The following are common ergative verbs from the Academic Word List. See Vocabulary: Selecting AWL




... and very large debts accumulated in the form of sterling balances.


... consciousness adapts to the practical needs of society.


his eyes had adjusted to the semidarkness


When it does so, the shape of the enzyme alters so that it no longer binds to S.


The last Russian assault commenced on 31 January.


As the liquid increased, the fabric contracted.


Heat caused the plastic to distort


As the family expands, the property it held before on an individual basis becomes communal property.


This chapter focuses mainly on agricultural emissions of methane and nitrous oxide.


The equipment inclined steeply.


The car reversed into the parking space.


Media attention has shifted recently.


The entertainment industry has transformed completely in recent years.

These are some other verbs that are commonly used in this way:

accelerate, begin, bend, boil, break, broaden, bruise, build up, burn, burst, change, close, combine, connect, cool, condense, crack, decrease, deflate, develop, diminish, disperse, drop, dry, end, enrol, evaporate, expand, finish, float, flood, fracture, freeze, grow, harden, ignite, improve, increase, industrialise, inflate, join, lengthen, lock, loosen, lower, melt, mend, merge, move, multiply, open, plunge, reload, reunite, revolve, rewind, rock, roll, run, scatter, separate, shake, shut, spill, spin, split, stand, start, stiffen, stop, strengthen, stretch, swing, tear, terminate, tighten, toughen, transfer, turn, turn on, turn off, twist, vaporise, weaken, whiten


Identify the ergative verbs in this text.

Water, in its different forms, cycles continuously through the lithosphere, hydrosphere, atmosphere, and biosphere. Water evaporates into the atmosphere from the land and the sea. Plants and animals use and reuse water and release water vapor into the air. Once in the air, water vapor circulates and cools and can condense to form clouds and precipitation, which fall back to earth. At one time or another, all of the water molecules on earth have been in an ocean, a river, a plant, an animal, a cloud, a raindrop, a snowflake, or a glacier.


Press this if you want to check your answers: Answers

Try this exercise: Grammar: Exercises Ergative.