Some words common in university and research writing do not normally have a plural form, and many cannot be used with a or an. These are called noncount nouns and a number of examples are given below:
education
Incorrect
educations
Examples of correct use
a university education
Education is very important.
Most universities offer a wide range of courses (not educations).
equipment
Incorrect
an equipment
equipments
Examples of correct use
a piece of equipment
The equipment was faulty.
Some of the equipment was damaged.
Much of the equipment was out of date.
evidence
Incorrect
an evidence
Examples of correct use
The evidence points to …
There is some evidence to suggest that …
There is a great deal of evidence for …
There is no evidence of …
information
Incorrect
an information
informations
Examples of correct use
an important piece of information
some information
Much of the information was incorrect.
We have no information on …
knowledge
Incorrect
knowledges
Examples of correct use
A knowledge of statistics is essential.
The author demonstrates an intimate knowledge of …
We now have a great deal of knowledge of …
We have little knowledge of …
progress
Incorrect
a progress
progresses
Examples of correct use
We have made limited progress.
We have made some progress.
We have made a great deal of progress towards …
We have made no progress.
research
Incorrect
a research
researches
Examples of correct use
an important piece of research
Further research is necessary …
Most of our research was carried out …
A great deal of research is concerned with …
software
Incorrect
a software
softwares
Examples of correct use
a computer program
We used the following software: