Noun Postmodification: Appositive Noun Phrases

Nouns are sometimes post-modified with other noun phrases. In academic writing these noun phrases are used provide to extra information, clarification, examples, formulae, and acronymsA short form of a phrase using the first letter of each word in the phrase. See the glossary definition . They may be enclosed by commas but are often enclosed in parentheses See the glossary definition , as in the examples below.

Appositive noun phrases are useful in printed text but with digital media there are other wayslike this (a popup), for example, or a glossary of supplying extra information.

1. Clarification

   A noun phrase in apposition is often used to give a definition or explanation of a word or phrase which the writer expects the reader might not know.

   • chitinhead noun phrase (the material that makes up the bulk of the exoskeleton of insects)appositive noun phrase containing a relative clause with two prepositional phrases      (context)In insects, these are found only in the scales of weevils, longhorn beetles, butterflies and moths, where they can form intricate arrays of chitin (the material that makes up the bulk of the exoskeleton of insects) and air.

   This quite long appositive noun phrase just explains what chitin is.

   
   

   • a planetary nebulahead noun phrase (essentially a cloud around the star)appositive noun phrase,      (context)The shell then becomes a planetary nebula (essentially a cloud around the star), while the carbon-rich core cools and becomes a “white dwarf”.

   This gives a brief (note the word "essentially") definition of a planetary nebula.

   
   

   • “cognitive flexibility”head noun phrase (our ability to shift perspective easily)appositive noun phrase      (context)These are important early building blocks for cognition, including “cognitive flexibility” (our ability to shift perspective easily), and are linked to wellbeing in later life.

   This gives a brief definition of “cognitive flexibility”.

   
   

2. Acronyms

   Acronyms are abbreviations of noun phrases which are likely to be repeated in a text or which have become part of common usage (e.g. DNA).

   • compact fluorescent lamphead noun phrase (CFL)appositive noun phrase in the form of an acronym      (context)Your tablet, phone, computer or compact fluorescent lamp (CFL) all emit this kind of blue light.

   • seasonal affective disorderhead noun phrase (SAD)appositive noun phrase in the form of an acronym      (context)In fact, a lack of sunlight can lead to a condition called seasonal affective disorder (SAD), sometimes called “winter depression”.

   • James Webb space telescopehead noun phrase (JWST)appositive noun phrase in the form of an acronym      (context) Nasa’s James Webb space telescope (JWST), is the largest telescope in space.

   
   

3. Formulae

Like acronyms, formulae are just shortened forms of longer phrases. Some of these, like mathematical formulae, would be quite complex to write out in full. The reason we use them is to pack a lot of information into a short space, which allows us treat a complex idea as a simple unit.

• the formulahead noun phrase 4πr²appositive noun phrase in the form of a formula      (context) To compute the surface area of the Earth, use the formula 4πr².

• methanehead noun phrase (CH₄)appositive noun phrase in the form of a formula, nitrous oxidehead noun phrase (N₂O)appositive noun phrase in the form of a formula     (context)Although CO₂ is the most abundant greenhouse gas, dozens of other gases – including methane (CH₄), nitrous oxide (N₂O) and the synthetic greenhouse gases – also trap heat.




4. Extra Information

   Sometimes appositive noun phrases are used to provide some extra information, useful or interesting but not strictly necessary, like dates, conversions to other units, Latin names, people's professions, etc.

   • Eratostheneshead noun phrase (276BC to 195 BC)appositive noun phrase giving a lifespan      (context)Eratosthenes (276BC to 195 BC) was chief librarian at the Great Library of Alexandria, and a keen experimentalist.

   • 3,959 mileshead noun phrase (6,371 kilometers)appositive noun phrase giving a conversion to kilometres      (context)Start with the basic assumption that the Earth is a sphere, recognizing that this is an approximate truth, and that its radius is approximately 3,959 miles (6,371 kilometers).

   • bitter vetchhead noun phrase (Vicia ervilia)appositive noun phrase giving a latin name, grass peahead noun phrase (Lathyrus spp)appositive noun phrase giving a latin name and wild peahead noun phrase (Pisum spp)appositive noun phrase giving a latin name     (context)At both sites, we often found ground or pounded pulse seeds such as bitter vetch (Vicia ervilia), grass pea (Lathyrus spp) and (Pisum spp).

   • the 18th-century English scholarhead noun phrase (Thomas Bayes)appositive noun phrase giving the name of the scholar      (context)This mental updating is expressed in a mathematical formula worked out by the 18th-century English scholar, (Thomas Bayes).

   • the same “big three” glaciershead noun phrase (Jakobshavn Isbrae in the west of the island and Helheim and Kangerlussuaq in the east)appositive noun phrase giving the names of the glaciers      (context)In 2013, a modelling study by Faezeh Nick and colleagues also looked at the same “big three” glaciers (Jakobshavn Isbrae in the west of the island and Helheim and Kangerlussuaq in the east) and projected how they would respond in different future climate scenarios.

   
   

5. Examples

   Examples of something mentioned, or lists of items in a category, are often placed in appositive noun phrases.

   • molluscshead noun phrase (snails, for example)appositive noun phrase or annelidshead noun phrase (earthworms)appositive noun phrase      (context)Finally, we have one lineage, the lophotrochozoans, that includes animals such as molluscs (snails, for example) or annelids (earthworms), among many others.

   • the five planets then knownhead noun phrase (Mercury, Venus, Mars, Jupiter, and Saturn)appositive noun phrase      (context)When manually rotated by a handle, the gears span dials on the exterior showing the phases of the Moon, the timing of lunar eclipses, and the positions of the five planets then known (Mercury, Venus, Mars, Jupiter, and Saturn) at different times of the year.