“My vocabulary is weak” is too broad to be useful. The problem may be word knowledge, retrieval, precision, qualification, evidence language, synthesis or tone—and each needs a different repair.
The complete JC1–JC2 vocabulary system becomes much more useful when students can locate the exact weak layer.
Eight diagnostic layers
- Recognition: can you understand the word when reading?
- Retrieval: can you produce it without notes?
- Boundary: can you distinguish it from near-synonyms?
- Collocation: can you use it naturally?
- Qualification: can you control scope and certainty?
- Argument: can vocabulary express claims, mechanisms and rebuttals?
- Synthesis: can you describe relationships between ideas?
- Transfer: can you use the concept in an unfamiliar topic?
Test with production, not confidence
Do not ask whether a student “knows” a word. Ask them to define it, contrast it, place it in a natural phrase, use it in a claim, then transfer it to a new domain. The first point of failure reveals the repair target.
Common diagnostic patterns
- Understands but cannot write: retrieval weakness.
- Uses advanced words inaccurately: boundary weakness.
- Sounds unnatural: collocation/register weakness.
- Writes sweeping claims: qualification weakness.
- Has examples but weak analysis: evidence/argument weakness.
- Memorises topic essays: transfer weakness.
Repair the earliest weak link
There is little value drilling sophisticated synthesis vocabulary if the student cannot reliably retrieve basic qualification language. Repair should begin at the earliest unstable layer, then test whether the improvement transfers forward.
The weekly diagnostic
Take ten active words and test definition, contrast, collocation, sentence use, argument use and topic transfer. Record the first failure for each word. Patterns emerge quickly.
A precise diagnosis turns “learn more vocabulary” into a teachable plan.
Diagnostic Lab: Find the First Unstable Layer
Vocabulary improvement accelerates when diagnosis identifies the first point where control breaks. A student may recognise a word, retrieve it slowly, misuse its boundary, combine it unnaturally or fail to transfer it into argument. Those are different problems.
The Control Ladder
- Recognition
- Definition
- Boundary distinction
- Collocation
- Retrieval
- Sentence use
- Argument use
- Transfer to unfamiliar topics
Test in that order. The earliest failure is usually the best repair target.
Diagnostic Pattern 1: Recognition Without Retrieval
The student understands proportionality when reading but cannot produce it while writing. Repair with cue-based retrieval and timed use, not more rereading.
Diagnostic Pattern 2: Retrieval Without Boundary Control
The student quickly uses legitimate but treats it as a synonym for legal. Repair through contrast sentences, evidence thresholds and near-neighbour discrimination.
Diagnostic Pattern 3: Word Knowledge Without Argument Transfer
The student can define resilience but only in a memorised climate example. Repair by transferring the concept to healthcare, finance, transport and families.
Diagnostic Pattern 4: Accurate Words, Weak Reasoning
If vocabulary is accurate but paragraphs remain descriptive, the problem is not vocabulary quantity. Test claim, mechanism, evidence, limitation and evaluation. The repair belongs in argument architecture.
Weekly Diagnostic Card
- 10 active words
- 2 near-synonym contrasts each
- 1 natural collocation each
- 1 timed sentence each
- 3 transferred concepts across unrelated topics
- 1 paragraph using at least four function families
Repair Before Expansion
Do not add fifty new words when ten existing ones remain unstable. Deep control over a smaller high-value network usually improves writing more than a larger passive list.
A useful diagnostic ends with a specific prescription: what failed first, what exercise repairs it, and what transfer test will show that the repair holds.
Use the complete JC vocabulary framework as the map for repair.