IELTS Listening · Ch 12
Flow-chart Completion
Cause-effect chains · transitional language · stage-by-stage tracking
Topic & Why It Matters
Flow-chart Completion asks you to listen to a process and complete missing stages, materials, actions, places, or outcomes in a chart connected by arrows. It appears most often in Part 2 or Part 4, where a speaker explains a procedure, a production method, an application system, or a research process.
The difficulty is not usually the vocabulary itself. Candidates lose marks because they stop following the arrows, miss a transition signal, or write an answer that means the right thing but does not fit the grammar of the blank. A strong flow-chart listener thinks in stages: input, action, result, next stage.
Knowledge Points
Flow-charts test sequence and logic
A flow-chart shows stages in a process, procedure, experiment, or decision path. Your job is to follow the order of events and fill missing words that complete each step.
Answers usually appear in order
Like most completion tasks, numbered blanks follow the audio sequence. If blank 3 is being discussed, blank 4 is probably coming soon, so keep your eyes moving down the chart.
Arrows are grammar
Arrows show cause-effect, sequence, or movement from one stage to the next. Read them as connectors: first this happens, then it leads to that, and finally the output is produced.
Predict the part of speech
The words before and after each blank tell you whether the answer is a noun, verb, adjective, material, place, or number. This is the fastest way to reject wrong-sounding distractors.
Paraphrase is built into the task
The printed chart may say 'initial stage,' while the speaker says 'the first thing researchers do.' Do not wait for exact wording; listen for equivalent meaning.
Cause-effect language signals movement
Words such as because, therefore, as a result, leads to, and enables often move you from one box to the next. These signals are especially common in Part 4 lectures.
Word limits still decide the mark
If the instruction says "NO MORE THAN TWO WORDS," then "a glass bottle" is too long. Write only the words that fit the blank and the limit.
Step-by-Step Strategy
1
Read the title first
Use the flow-chart title to identify the process: manufacturing, research method, application procedure, or environmental cycle.
2
Trace the arrows silently
Before the audio starts, move from box to box with your finger or eyes. Notice branches, repeated stages, and final outputs.
3
Predict each blank type
Look at grammar around the gap: 'add ___' needs a noun, 'is ___' may need an adjective or past participle, and 'at ___ degrees' needs a number.
4
Underline fixed anchors
Mark technical words, stage names, dates, and nouns already printed in the chart. The speaker will often paraphrase around these anchors.
5
Follow transition signals
Use first, after that, once, before, because, therefore, and finally to know when the speaker has moved to the next box.
6
Write only the missing content
Do not copy surrounding printed words. If the chart says 'kept in ___ boxes,' write 'cardboard,' not 'cardboard boxes.'
7
Check grammar during transfer
In the final check, read each completed box as a sentence fragment. The answer should fit grammatically and respect the word limit.
Common Pitfalls
| Mistake | Corrective Rule |
|---|---|
| Missing a branch in the chart | Check whether arrows split into alternatives; one branch may be skipped or mentioned after a condition. |
| Writing a paraphrase instead of the heard answer | Use the exact word or phrase from the audio when possible, even if the chart uses different wording. |
| Ignoring grammar around the blank | If the chart reads 'stored in ___,' the answer should be a place or container, not a verb. |
| Following meaning but losing numbering | Always keep one eye on the next blank number; the process order and the question order are usually the same. |
| Adding extra articles | Articles count as words. If the audio says "a drying room" and the limit is two words, write "drying room." |
Vocabulary Bank
| Expression / Signal | Usage Note |
|---|---|
| first / initially | Introduces the opening stage |
| the next stage / step | Signals movement to the next box |
| once / after / before | Time relationship between stages |
| then / subsequently | Sequential movement |
| finally / at the end | Final output or last stage |
| leads to / results in | Cause-effect arrow |
| because / since / as | Reason for a stage or decision |
| therefore / so / as a result | Consequence or outcome |
| is transferred to | Movement from one location or container to another |
| is separated from | One material or group is removed from another |
| is heated / cooled / dried | Common process verbs in passive form |
| raw material | Input at the beginning of a manufacturing process |
| sample | Material collected for testing or analysis |
| container / tank / tray | Common answer category for storage stages |
| quality check | Inspection stage before final packaging or approval |
| output / product | The result at the end of the flow-chart |
Practice Question
Instructions: Complete the flow-chart below. Write NO MORE THAN TWO WORDS for each answer. Click Check when done.
1. Inspection
→2. Washing
→3. Cutting
→4. Tray loading
→5. Drying
→6. Checking
→7. Packaging
Audio Script — Dried Apple Snacks
■ Lecturer (male)In the real test you hear this once. Play first and attempt the exercise, then read the script to verify.
Model Answer
| Answer | Explanation |
|---|---|
| 1. bruising | The lecturer says workers check the apples for bruising and remove fruit with damaged skin. The word after the blank is not printed, so the noun 'bruising' completes the purpose of the check. |
| 2. cold | The apples are washed in cold water. The speaker contrasts this with warm water, which is a distractor because it is mentioned only as something they avoid. |
| 3. slices | After washing, the apples are cut into thin slices by a rotating blade. 'Large chunks' is a distractor because the speaker says slices dry better than chunks. |
| 4. metal | The slices are placed on metal trays. Plastic trays are rejected in the audio, so the material that fits the printed word 'trays' is 'metal.' |
| 5. drying room | The trays are moved into a drying room where warm air removes moisture. The phrase is two words, so it fits a 'NO MORE THAN TWO WORDS' instruction. |
| 6. quality | Before packaging, the slices go through a final quality check. The printed word 'check' is already on the chart, so only 'quality' should be written. |
| 7. paper | The approved pieces are packed in paper bags. Plastic packets are mentioned as an old method, so 'plastic' is the distractor and 'paper' is the current answer. |
Self-Check
Answer these from memory before looking back. If you cannot answer all three, re-read the relevant section.
- What should you trace before the audio starts in a flow-chart task?
- Why is 'warm' the wrong answer for blank 2 in the practice question?
- If the chart says 'final ___ check,' why should you write only 'quality'?
Answers: (1) Trace the arrows and stage order. (2) The speaker says warm water is avoided; the apples are washed in cold water. (3) "Check" is already printed, so only the missing modifier "quality" should be written.