A very common way to modify a noun is with another noun. These noun + noun structures are tricky because students are often unsure whether to choose a noun or adjective as a modifier. Consider the underlined words in these sentences:

  • That’s a grammar book.
  • That’s a grammatical sentence.

In the first sentence, grammar classifies the noun: it tells us what kind of book it is. Noun modifiers often have this function of classification. On the other hand, the adjective form grammatical describes a characteristic of the sentence and has a slightly different meaning from its related noun. Therefore, when the modifier expresses the category, class, or type, it is usually a noun, especially if the related adjective would change the meaning.

Noun modifiers are also used when referring to academic subjects, such as a chemistry course (not a chemical course), a history paper (not a historical paper), and a business plan. Students may need help with nouns like physics and linguistics, which unusually are non-count nouns ending with an -s.

Learners should also pay attention to subject-verb agreement: the verb agrees with the main noun, not the modifier. This is important because noun modifiers are almost always singular while the main noun might be plural.

Book clubs are a popular way to meet interesting people.
A college degree is required for this job.

In addition, articles are used only if the main noun needs them:

The Internet can be used for this paper.
Internet sources can be used for this paper.

Although a definite article is needed with the noun Internet, in the second sentence the main noun is sources, which does not take an article.

The downloadable contains exercises to practice these noun + noun patterns.