Mastering IELTS Flowchart Vocabulary for Reading
Flowchart questions in IELTS Reading are often underestimated. Many candidates focus only on scanning for answers, but the real challenge lies in understanding process language—how actions, sequences, and transformations are described.
A flowchart is not just a diagram—it is a compressed version of a process passage. To succeed, you must:
- Recognize paraphrased verbs
- Track sequence and logic
- Predict grammar (POS: noun, verb, adjective)
This article provides a complete vocabulary system to help you decode any flowchart efficiently.
Category 1. Verbs Intake/Start
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Collection | collect | gather, harvest, pick up, source, obtain | “Researchers collect samples from wells.” | verb (base) | Often the first step; sometimes appears as a noun (“collection”). |
| Intake | receive | accept, take in, intake | “The plant receives untreated water.” | verb | Pair with nouns like shipments, materials, orders. |
| Intake | retrieve | fetch, recover, draw | “Sensors retrieve data hourly.” | verb | Technical tone common in academic texts. |
Keynote. These verbs describe the beginning of a process—where materials, data, or inputs enter the system.
| Example | Practice 1 | Practice 2 |
“The system receives raw data from sensors.” Flowchart: | Fill the blank: The machine ________ raw materials from external suppliers. (Expected: receives / collects / obtains) | Match the paraphrase:
(Answers: recover, gather) |
Category 2. Verbs – Transport/Movement
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Conveyance | transport | carry, convey, move, transfer, deliver, channel | “Materials are transported via pipeline.” | verb (passive often) | If the blank follows “are…”, expect past participle. |
| Conveyance | pump | drive, push, circulate | “Water is pumped to a header tank.” | verb | Collocates with through/to/into. |
| Transfer | pour | decant, dispense, tip, transfer (liquid) | “The solution is poured into molds.” | verb | Often tied to containers/molds. |
Keynote. These describe how something moves between stages.
| Example | Practice 1 | Practice 2 |
“Water is pumped into a storage tank.” Flowchart: | Materials are ________ via conveyor belt. (transported / conveyed) | Choose correct form: Liquid is ________ into containers. (poured)
|
Category 3. Verbs – Physical Change
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Size/Shape | crush | grind, mill, pulverise, fragment | “Ores are crushed before smelting.” | verb | Look for equipment cues: mill, crusher. |
| Size/Shape | cut | slice, chop, shear, trim, shred | “Leaves are shredded for analysis.” | verb | Often before drying, extraction. |
| Thermal | heat | warm, raise temperature, roast, bake, boil | “The mixture is heated to 90°C.” | verb | Check for temperature values. |
| Thermal | melt | liquefy, fuse | “Wax melts at low temperatures.” | verb | Pair with solid → liquid transitions. |
| Thermal | cool | chill, freeze, quench | “Metal is cooled rapidly.” | verb | Often followed by to X°C. |
| Phase | evaporate | vaporise | “Solvent evaporates during drying.” | verb | Signals loss/removal of liquid. |
| Phase | condense | liquefy (gas→liquid), precipitate (chem.) | “Vapour condenses in the coil.” | verb | Often paired with coil, condenser. |
| Phase | solidify | set, harden, cure | “The resin solidifies in minutes.” | verb | Collocates with mold, cast. |
Keynote. These verbs describe transformation (shape, temperature, state).
| Example | Practice 1 | Practice 2 |
“The mixture is heated to 90°C.” Flowchart: | The metal is ________ rapidly after heating. (cooled / quenched) | Wax ________ when temperature increases. (melts)
|
Category 4. Verbs – Mixing/Separation
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Mixing | mix | blend, combine, integrate, homogenise, stir, agitate | “Ingredients are mixed thoroughly.” | verb | Watch for adverbs: thoroughly, gently. |
| Mixing | dilute | thin, weaken | “Acid is diluted with water.” | verb | Look for ratios/percentages. |
| Mixing | concentrate | reduce, thicken, condense | “Juice is concentrated by boiling.” | verb | Often a result of evaporation. |
| Separation | filter | sieve, screen, strain, membrane | “Liquid is filtered to remove solids.” | verb | Noun form filter frequently answers blanks. |
| Separation | separate | split, isolate, partition, segregate | “Components are separated by density.” | verb | Often followed by by/according to. |
| Separation | extract | remove, draw out, leach | “Oil is extracted with solvents.” | verb | Common in scientific flows. |
Keynote. Processes often involve combining or separating elements.
| Example | Practice 1 | Practice 2 |
| “The liquid is filtered to remove impurities.” | The ingredients are ________ thoroughly. (mixed / blended)
| Oil is ________ from seeds. (extracted) |
Category 5. Verbs – Measurement/Control
| Measure | measure | gauge, quantify, determine | “They measure pH every hour.” | verb | May appear as a noun: measurement. |
| Control | adjust | tune, calibrate, regulate, set | “Valves are adjusted to maintain pressure.” | verb | Look for target setpoints. |
| Monitor | monitor | track, record, log, observe | “Teams monitor emissions.” | verb | Continuous/ongoing step. |
Keynote. These indicate monitoring and adjustments.
| Example | Practice 1 | Practice 2 |
| “Pressure is monitored continuously.” | Temperature is ________ every hour. (measured) | Valves are ________ to control flow. (adjusted) |
Category 6. Verbs – Quality/Packaging
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Test | test | analyse, assay, evaluate, assess | “Batches are tested for purity.” | verb | Look for criteria/standards. |
| Label | label | tag, mark, code, barcode | “Specimens are labelled at receipt.” | verb | Spelling: UK labelled / US labeled. |
| Pack | package | pack, seal, wrap, bottle, can | “Goods are packaged and shipped.” | verb | Often final step before distribution. |
| Ship | distribute | dispatch, deliver, send | “Orders are dispatched daily.” | verb | Often paired with finally. |
Keynote. These are usually the final stages.
| Example | Practice 1 | Practice 2 |
| “Products are packaged and shipped.” | Items are ________ before delivery. (tested / labelled) | Goods are ________ to customers. (distributed / dispatched) |
Category 7. Nouns – Inputs/Outputs
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Inputs | material | raw material, feedstock, input, ingredient, component | “Raw materials arrive in crates.” | noun | Plural common in industrial texts. |
| Batches | batch | lot, consignment, run | “Each batch is tested twice.” | noun | Pairs with number, code. |
| Samples | sample | specimen, aliquot, extract | “Soil samples are refrigerated.” | noun | Lab/field contexts. |
| Outputs | product | output, yield, by-product, co-product | “The main product is ethanol.” | noun | “By-product” often answers blanks. |
| Waste | waste | residue, refuse, sludge, scrap, tailings | “Toxic waste is contained.” | noun | Environmental contexts. |
Keynote. Flowchart answers are often nouns, not verbs.
| Example | Practice 1 | Practice 2 |
| “The liquid passes through a filter.” | Raw ________ are processed in the plant. (materials) | The process takes place in a large ________. (facility / unit) |
Category 8. Nouns – States/Mixtures
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Mixes | mixture | blend, solution, suspension, slurry, emulsion | “A solution of salt is prepared.” | noun | Match exact text wording. |
| Solids/Liquids | precipitate | deposit, sediment | “A white precipitate forms.” | noun | Chemistry passages. |
| Filtration | filtrate | permeate, retentate (membranes) | “The filtrate is collected.” | noun | Technical register. |
Keynote. These words define order and reasoning.
| Example | Practice 1 | Practice 2 |
| “First, the seeds are washed. Then they are dried.” | ________, the mixture is heated. (Then / Next) | The temperature rises; ________, pressure increases. (therefore) |
Category 9. Nouns – Equipment
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Vessels | tank | vessel, container, reactor, chamber | “Stored in a tank.” | noun | Pair with storage, mixing. |
| Flow | pipeline | pipe, duct, channel, conduit | “Through a pipeline to the unit.” | noun | Often with verbs pump/convey. |
| Separation | filter | sieve, screen, membrane | “Across a membrane.” | noun | Equipment often the answer. |
| Thermal | furnace | kiln, oven, heater | “Into the kiln at 900°C.” | noun | High-temp processes. |
| Cooling | heat exchanger | cooler, radiator | “A heat exchanger reduces temp.” | noun | Two-word technical noun fits “≤3 words”. |
| Motion | conveyor | belt, hopper, chute, feeder | “On a conveyor to packing.” | noun | Manufacturing settings. |
| Rotation/Force | centrifuge | press, compactor | “Spun in a centrifuge.” | noun | Separation by density. |
| Flow control | pump | valve, nozzle, manifold | “Via a valve to line B.” | noun | Valve is frequent. |
| Sensing | sensor | probe, meter, gauge, detector | “A sensor records pressure.” | noun | Precise one-word answers. |
Keynote. These describe state, condition, and data.
| Example | Practice 1 | Practice 2 |
| “The solution is heated to 80°C.” | The material is in ________ form. (liquid / solid) | Heat for 10 ________. (minutes) |
Category 10. Nouns – Places/Units
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Sites | facility | plant, site, works, complex | “At the facility.” | noun | Often generic location. |
| Sub-areas | unit | station, line, cell, module | “Transferred to Unit 3.” | noun + number | Expect numbers with units. |
Category 11. Connectors – Sequence
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Order | first | initially, at the outset | “First, wash the seeds.” | adverb | Signals flow start. |
| Order | then | next, afterwards, subsequently, following this | “Then heat the mixture.” | adverb | Appears in instructions. |
| Simultaneity | meanwhile | concurrently, at the same time | “Meanwhile, filters are replaced.” | adverb | Parallel branch cue. |
| End | finally | ultimately, in the end, at last | “Finally, package the goods.” | adverb | Final step marker. |
Category 12. Connectors – Logic
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Cause/Effect | therefore | thus, hence, as a result, leading to, resulting in | “Humidity rises, therefore mold forms.” | connector | Often bridges step → outcome. |
| Condition | if | when, in case of, depending on, otherwise | “If levels fall, add solvent.” | connector | Decision diamonds in logic. |
| Contrast | however | although, whereas, while, unlike | “However, small batches differ.” | connector | Signals exception branch. |
| Addition | also | in addition, moreover, furthermore | “Also, inspect seals.” | connector | Adds optional steps. |
Category 13. Adjectives/States
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Condition | raw | fresh, unprocessed, untreated | “Raw materials” | adj. | Opposite: processed/refined. |
| Purity | pure | clean, sterile, uncontaminated, refined | “Purified water” | adj./participle | Often from filtering step. |
| Contamination | contaminated | dirty, impure, tainted | “Contaminated runoff” | adj. | Often leads to treatment. |
| Temperature | hot | warm, cold, chilled, frozen | “Hot gases” | adj. | Pair with °C data. |
| Phase | liquid | solid, gaseous, vapour | “Liquid phase” | adj./noun | Scientific register. |
| Texture | coarse | fine, thick, thin, viscous | “Viscous slurry” | adj. | Often post-mixing. |
| Stage | initial | intermediate, final | “Final product” | adj. | Maps to flowchart columns. |
| Mode | manual | automatic, digital | “Automatic shut-off” | adj. | Process control. |
| Sustainability | recycled | renewable, sustainable | “Recycled plastic” | adj. | Environmental texts. |
Category 14. Measurements
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Time | minutes | seconds, hours, days, weeks | “Heat for 10 minutes.” | number + noun | Counts as 2 words. |
| Temperature | °C | degrees Celsius, temperature | “At 80°C” | number+symbol | Digits + symbol count as 1. |
| Pressure | pressure | bar, kPa, vacuum | “Low pressure chamber” | noun | Might be numeric too. |
| Quantity | amount | volume, weight, mass | “Small volume added.” | noun | Watch unit abbreviations. |
| Concentration | % | percentage, ppm, molarity | “Salt at 5%.” | number+symbol | Often one token. |
| Dimensions | diameter | length, width, thickness | “Pipe diameter 2 cm.” | noun | Common in engineering passages. |
| Rate | flow rate | speed, throughput, frequency | “High flow rate.” | noun (2 words) | Check word-limit rules. |
Category 15. People/Agents
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Roles | operator | technician, engineer, supervisor | “The operator initiates purge.” | noun | Human-initiated steps. |
| Groups | team | department, unit, staff | “Quality team inspects.” | noun | Could be agent of a step. |
Category 16. Outcomes/Logic
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Results | result | outcome, effect, consequence | “This results in cooling.” | noun/verb | Cause→effect links. |
| Decision | decision | choice, selection, evaluation | “Make a decision to reroute.” | noun | Often at branches. |
Category 17. Common Phrases
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Step cues | pass through | go through, move through | “Liquids pass through filters.” | phrasal verb | Very frequent in flow descriptions. |
| Addition | add | introduce, inject, dose | “Add catalyst.” | verb | Often followed by to + noun. |
| Removal | remove | eliminate, strip, purge | “Remove impurities.” | verb | Removal steps precede purify. |
| Transfer | transfer to | move to, send to, direct to | “Transfer to reactor.” | verb phrase | Destination often a unit name. |
| Storage | store in | keep in, hold in | “Stored in sealed drums.” | verb phrase | Storage before distribution. |
Category 18. Flowchart Cues
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Visual | arrow | flow arrow, direction arrow | “Arrow indicates flow.” | noun | In text, “flow to/into” is hint. |
| Choice | branch | split, route, pathway | “Process branches at valve.” | noun/verb | Signals conditional steps. |
| Loop | cycle | repeat, iterate, recirculate | “System recirculates fluid.” | noun/verb | “Repeat until…” cues loop. |
Category 19. Exam Tips
| Subcategory | Common Term | Paraphrases / Variants | Example in Passage | Likely Answer Slot (POS) | Notes / IELTS Tips |
| Word limits | hyphen | hyphenated word counts | “heat-resistant” (1 word) | — | Hyphenated = one word in IELTS. |
| Grammar | POS fit | noun/verb/adjective fit | Article + noun | — | Use surrounding grammar to predict POS. |
| Paraphrase | synonyms | reworded steps | “separate” → “isolate” | — | Match meaning, not surface word. |
| Numbers | format | digits vs words | “5°C” vs “five degrees” | — | Prefer the form used in passage. |
Strategy Notes.
1. Think in Processes, Not Words
Flowcharts test your ability to:
- Understand sequence
- Recognize paraphrasing
2. Always Predict the Answer Type (POS)
| Clue | Likely Answer |
| “is ___” | past participle verb |
| “a ___” | noun |
| “very ___” | adjective |
3. Follow the Flow
- Start → Middle → End
- Don’t jump randomly
- Answers follow passage order
4. Watch for Paraphrases
Example:
- passage: “separate”
- flowchart: “isolate”
Keynote. Same meaning, different word
5. Respect Word Limits
- “heat-resistant” = 1 word
- “10 minutes” = 2 words
Practices
Practice 1: Fill the Flow
- Raw materials are ________ from suppliers.
- They are then ________ to the factory.
- Next, they are ________ and impurities are removed.
- Finally, products are ________ and distributed.
Practice 2: Identify the Process
Read:
“The liquid is heated, then cooled rapidly before being filtered.”
Order the steps:
Final Keynote
If you master: Verbs of process, Nouns of systems and Logical connectors; Flowchart questions become predictable and mechanical, not difficult.
