Definite and Indefinite Articles | When to Use "The", "A" or "An"

English has two types of articles to precede nouns: definite (the) and indefinite (a/an). You can improve the articles that appear in your dissertation by:

  • not using unnecessary articles with plural nouns,
  • not using “a” or “an” with uncountable nouns,
  • using articles with singular countable nouns,
  • correctly choosing “a” or “an” in front of an acronym,
  • correctly deciding if an acronym for an entity needs “the,”
  • correctly identifying if a country name needs “the.”

Avoid using unnecessary articles with plural nouns

If you are using a plural noun (such as students, criteria, or theses), you usually don’t need to use “the.”

Incorrect Correct
The researchers have commonly found that Researchers have commonly found that
The studies were undertaken to determine Studies were undertaken to determine

The exception is if you want to distinguish that you are talking about a particular group of people or things.

Example Explanation
This topic has been investigated by teams at many top universities. The researchers have commonly found that You are talking specifically about work undertaken by certain teams (and not about researchers in general).
The department conducted numerous studies with the funding. The studies were undertaken to determine You are referring specifically to the studies that were undertaken in this context (as opposed to studies in general).

Don’t use “a” or “an” with uncountable nouns

As the term implies, an uncountable (or mass) noun is something that normally cannot be counted (such as air, anger, information, knowledge, research, rice, and training).

Uncountable nouns cannot be accompanied by “a” or “an,” as it’s impossible to have one of these things. If you really want to talk about one of something, the easiest option is to replace the uncountable noun with one that is countable. Another option is to add a countable noun after the uncountable noun.

Incorrect Correct alternatives
A research showed that A study showed that

A research project showed that

A training was held A class was held

A training course was held

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Use an article (or other determiner) with a singular countable noun

Singular countable nouns (such as formula, participant, and professor) generally cannot stand on their own. If you are not using a possessive (e.g., my, your, her) or a demonstrative (e.g., this, that), you should use an article or other determiner.

Incorrect Alternatives
In interview it was revealed that In his interview it was revealed that

In that interview it was revealed that

In the interview it was revealed that

In an interview it was revealed that

We tested hypothesis before we We tested our hypothesis before we

We tested this hypothesis before we

We tested the hypothesis before we

We tested a hypothesis before we

Correctly choose “a” or “an” in front of an acronym

Most writers know that words starting with a consonant sound need “a” (e.g., a study, a participant, a European), while words starting with a vowel sound need “an” (e.g., an observation, an interview, an Ethiopian).

The same is true with acronyms (or initialisms), which are formed using the first letter of a series of words (such as SWOT for strengths, weaknesses, opportunities, and threats). When deciding whether “a” or “an” is appropriate, focus on how the acronym would be pronounced. For instance, at first glance it might seem like “a HR manager” is right; however, given the way it is read, “an HR manager” is the correct choice.

Examples acronyms with a/an

Many employees earned an MBA or a PhD from an EU-accredited program.

After it creates an R&D department, the agency plans to apply for an FAO grant.

Having an HQ abroad can be difficult for a company with a HEPNET project.

Correctly decide if an acronym for an entity needs “the”

Acronyms that relate to organizations and countries have their own special guidelines when it comes to “the.”

The general test is whether an acronym would be read letter by letter (as in ADB) or pronounced as a word (as in NATO). Acronyms that are read letter by letter usually need “the”:

Examples acronyms with “the”

The headquarters of the UN are in the US.

Several delegations from the EU have visited the UAE.

In contrast, acronyms that are read as words normally do not need “the”:

Examples acronyms without “the”

The secretary-general of OPEC used to work at UNESCO.

Officials from FIFA are currently under scrutiny.

Correctly identify if a country name needs “the”

Most country names do not need an article. For instance, we say “The researcher traveled to Zimbabwe” or “The study was conducted in Thailand.” However, “the” is needed in the following circumstances:

Country rule Example
When the country’s name includes a common noun, such as Federation, Kingdom, Republic, or State the Central African Republic

the Czech Republic

the Democratic People’s Republic of Korea

the Dominican Republic

the Kingdom of Bhutan

the Republic of Korea

the Russian Federation

the United Kingdom

When the country’s name is a plural noun or contains a plural noun the Bahamas

the Federated States of Micronesia

the Maldives

the Marshall Islands

the Netherlands

the Philippines

the Solomon Islands

the United Arab Emirates

the United States

By tradition the Gambia

Note that when it comes before a country name, “the” does not need to be capitalized.

Sources in this article

We strongly encourage students to use sources in their work. You can cite our article (APA Style) or take a deep dive into the articles below.

This Scribbr article

Vinz, S. (October 10, 2022). Definite and Indefinite Articles | When to Use "The", "A" or "An". Scribbr. Retrieved October 19, 2022, from


Aarts, B. (2011). Oxford modern English grammar. Oxford University Press.

Butterfield, J. (Ed.). (2015). Fowler’s dictionary of modern English usage (4th ed.). Oxford University Press.

Garner, B. A. (2016). Garner’s modern English usage (4th ed.). Oxford University Press.

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Sarah Vinz

Sarah's academic background includes a Master of Arts in English, a Master of International Affairs degree, and a Bachelor of Arts in Political Science. She loves the challenge of finding the perfect formulation or wording and derives much satisfaction from helping students take their academic writing up a notch.