5.1 Metaphor and Idiom

Key Takeaways

  • NBT Academic Literacy treats metaphor, idiom, connotation, word play, and ambiguity as reading skills inside an academic argument, not as optional decoration.
  • An academic metaphor maps a source image onto a target topic so the reader can see a relation such as blockage, access, or extraction.
  • Connotation is the attitude a word carries; scare quotes and verbs such as claims or boasts often mark scepticism.
  • Idioms in university English (take stock, raise the bar, in the wake of) must be read as conventional meanings, not as word-by-word pictures.
  • Independent OpenExamPrep examples on this page train the method; they do not copy confidential NBT items or official booklet passages.
Last updated: September 2026

5.1 Metaphor and Idiom

Quick Answer: On the Academic Literacy (AL) component of the National Benchmark Tests (NBT) Academic and Quantitative Literacy (AQL) paper, metaphor and idiom items test whether you can read connotation, word play, ambiguity, and idiomatic expressions as part of an academic claim. Treat the image as machinery for the argument, not as wallpaper.

Academic English is full of language that does not mean exactly what a dictionary's first sense would suggest. A metaphor maps one domain onto another so a reader can see a relationship: a clinic as a filter, a degree as a pipeline, paperwork as a toll-gate. An idiom is a conventional phrase whose meaning is not the sum of its words (take stock, raise the bar, move the goalposts). Connotation is the attitude a word smuggles in (claimed versus showed; paltry versus small). Word play and ambiguity appear when a writer leans on two senses of a word at once, often to criticise or to ironise.

NBTP's public description of AL includes making meaning from tertiary-style text and understanding vocabulary in context. Teacher-facing notes on the AL subdomains are more specific: academic writers use connotation, word play, ambiguity, and idiomatic expressions, and the reader has to notice what those devices are doing in the passage. This independent OpenExamPrep section trains that reading skill with original examples. It is not an official NBT paper, and it does not copy the well-known advertising-passage teaching example from public booklet discussion. The method is what transfers: name the image, name the academic object, name the attitude.

Academic metaphor is not decoration

School literature lessons sometimes treat metaphor as ornament: a sunset painted the sky. University reading treats metaphor as conceptual machinery. If a public-health article writes that a township clinic is "the first filter of a health system" and that "when that filter clogs, the whole network backs up," the writer is not describing plumbing. The mapping is: primary clinic to filter; overload to clogging; hospitals to the rest of the network. The academic claim is about sequence and pressure in a referral system. If you paraphrase the sentence as "the clinic has a water filter," you have kept the vehicle and thrown away the tenor.

A useful exam habit is to name source (the image), target (the academic topic), and relation (what the writer wants you to accept).

Sentence in a passageSource imageTarget topicRelation the writer is arguing
The generator is the oxygen of the practicalOxygen / breathingLaboratory teaching during outagesWithout backup power the practical cannot run
NSFAS is a bridge into campus, but the bridge is toll-gated by paperworkBridge and tollStudent funding accessEntry exists, yet administrative cost blocks it
The literature review is scaffolding, not the buildingScaffolding versus finished structureAcademic writingCitations support work; they are not the contribution
Load-shedding is a bottleneck at the HPLCBottleneckResearch throughputA constraint at one point slows the whole process

Notice what these metaphors hide as well as what they show. Calling a funding scheme a bridge emphasises connection; calling the paperwork a toll emphasises cost. A later sentence that called the same scheme a safety net would shift the mapping from travel to protection. AL items often ask which paraphrase keeps the mapping, or which inference the image supports.

Worked original example (written for this chapter, not taken from any official booklet):

When a first-year chemistry laboratory runs on a generator during load-shedding, the generator is not a luxury. It is the oxygen of the practical. Cut the oxygen, and the module suffocates: titrations stop, data sheets stay blank, and the pipeline of students into second-year physical chemistry narrows to a trickle.

Questions you should be able to answer from that paragraph alone:

  • What is oxygen doing? It marks an enabling condition, not a reagent in the titration.
  • What happens if you read pipeline as oil infrastructure? You invent a topic the paragraph never mentions.
  • What claim is organised by narrows to a trickle? Throughput into the next course falls, and the fall is caused by interrupted practicals, not by a change in the official syllabus wording.

Public discussion of NBT-style teaching often uses an advertising-as-web pattern: a trapping or weaving image argues that consumers are caught, not merely informed. Do not memorise someone else's passage. Practise the same move on the passage in front of you.

Connotation: the attitude inside the word

Denotation is the relatively stable core meaning. Connotation is the evaluative colour. Academic writers choose verbs that already contain a verdict.

Neutral or cautious wordingLoaded wordingAttitude smuggled in
The brochure states that the tonic supports wellnessThe brochure boasts that the tonic supports wellnessScepticism; the writer doubts the boast
Staff reduced contact timeStaff slashed contact timeHostility toward the cut
The sample was smallThe sample was paltryThe size is judged inadequate, not merely reported
Students gathered in the hallStudents packed the hallDensity and pressure, not a calm meeting

On AL items, a question may look like a vocabulary item but is actually a connotation item: "In this paragraph, harvested most nearly suggests..." If the passage describes a company harvesting user data, the agricultural metaphor plus the cold verb often connotes extraction, not gardening.

Watch scare quotes. In "the dean's 'refresh' of the curriculum," the quotes are not decoration. They signal that the writer does not accept the official label. The word play is refresh in marketing-speak versus refresh as genuine renewal. The academic point is usually that packaging changed while contact time did not.

Word play and ambiguity

Lexical ambiguity is one word with two relevant senses. Syntactic ambiguity is a sentence that can attach a phrase two ways ("The committee attacked the lecturer with the new rubric" — who held the rubric?). Academic writers sometimes keep a double meaning on purpose.

Original example: "The faculty opened the door to rural applicants, then moved the goalposts by adding an unpaid winter camp." Opened the door is an idiom of access. Moved the goalposts is an idiom of unfair rule-change. Together they argue bad faith: an invitation plus a new barrier. If an item asks what moved the goalposts implies, the answer is not about sport. It is about changing criteria after people have already started the process.

Another original example: "Her 'contribution' to the group assignment was a cover page." The scare-quoted noun plays on the marking criterion contribution. The writer uses the official term against the student. That is criticism, not a typing quirk.

Exam trap: choosing a paraphrase that keeps only the funny sense and drops the argument. Humour can be a vehicle. AL still wants the claim.

Idiomatic expressions in academic prose

University English is thick with idioms that lecturers treat as transparent and that additional-language readers may parse word by word.

Idiom in academic EnglishWhat it is doing in a passageLiteral trap
on the other handSignals contrast between two claimsInventing a second physical hand
take stock ofPause and evaluateCounting livestock
raise the barIncrease the standardA high-jump apparatus
in the wake ofAfter, and as a consequence ofWater behind a boat
at face valueWithout checking underlying evidenceA face on a coin
the lion's shareThe largest portionAn actual lion

Idioms can also stack with metaphor. "After the strike, management had to take stock of which modules could still be examined in November" uses take stock as an evaluative idiom, not as warehouse inventory. The academic task is November assessment planning.

How AL items typically probe this skill

You will not be asked to invent a metaphor of your own. You will be asked to:

  1. Choose the paraphrase that preserves the mapping.
  2. Identify the writer's attitude (approval, irony, alarm, neutrality).
  3. Separate a conventional idiom from a one-off image.
  4. Reject options that are true in the world but unsupported by the passage's language.

A reliable routine: underline the non-literal stretch; write a five-word literal restatement; check which option matches that restatement; discard options that import extra facts (statistics, laws, emotions) the sentence does not license.

Independent OpenExamPrep quizzes below use original sentences. Official NBT questions are confidential; NBTP publishes separate exemplars on nbt.ac.za. Use those exemplars for format familiarity, then practise the reading moves here.

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Reading non-literal language in an Academic Literacy passage
Test Your Knowledge

In the sentence "The university's outreach programme is a bridge between high-school laboratories and first-year science, but the bridge is one-way: school learners visit campus, yet campus rarely visits the schools," the metaphor mainly does which academic job?

A
B
C
D
Test Your Knowledge

In "The committee tabled the report, and then buried it in an annexure," what is the best Academic Literacy reading of tabled and buried?

A
B
C
D
Test Your Knowledge

Which sentence uses an idiom as academic argument rather than as empty decoration?

A
B
C
D