ENGLISH · LESSON 12 OF 20
Explain a process and report completed work
What this lesson helps you do
Describe a sequence accurately, with clear units and a deliberate choice of time and voice.
Before this lesson
This lesson builds on:
The explanation
A process description explains how stages relate. Start with the input and destination, then follow a meaningful order. Use sequence expressions where they help, but avoid beginning every sentence with then. A reference such as the combined stream can connect stages naturally.
A general description often uses the present tense; a record of completed work commonly uses the past. Active and passive forms can both be appropriate. “The mixer combines the streams” and “The streams are combined” differ in focus. Neither is automatically more accurate. Preserve the actual method, measurements and conditions when writing a real report.
Numbers need units and a clear basis. In a mass-fraction example, 20% by mass means 20 units of solute mass in 100 units of total solution mass. A language model should not conceal an arithmetic inconsistency. The worked calculation below is an invented idealised mixer with no accumulation, reaction or material loss; it is not a laboratory operating procedure.
Language pattern
- Pattern
- Identify the input → describe the sequence → give the output → state relevant assumptions.
- What it does
- Help the reader follow both language and physical meaning.
- Limits
- Use only the real method and conditions in an actual report. Never invent a completed procedure.
A first worked example
Explain an idealised mixer
Situation. Invented data: feed A is 100 kg/h and contains 20% solute by mass; feed B is 50 kg/h of pure water. There is one outlet and no accumulation or loss.
Two streams enter an idealised mixer. Feed A flows at 100 kg/h and contains 20% solute by mass, while feed B supplies 50 kg/h of pure water. The streams combine to produce an outlet flow of 150 kg/h. The solute flow remains 20 kg/h, giving an outlet mass fraction of 20/150, or approximately 13.3%. This calculation assumes no accumulation, reaction or material loss.
Why it works
- The inputs are named before the output.
- While contrasts the two feed compositions without suggesting a time conflict.
- 100 × 0.20 gives 20 kg/h of solute; 100 + 50 gives 150 kg/h total.
- Approximately signals rounding of 13.333…%.
What it shows: The paragraph communicates a model and its assumptions, not a claim that an experiment was performed.
A second worked example
Describe completed work with the correct focus
Situation. Invented completed classroom activity: a student team compared two supplied graphs and documented their labels.
The team compared the two supplied graphs and recorded the axis labels in a table. Each value was checked against its stated unit before the comparison was written.
Why it works
- Past tense identifies completed work in this fictional example.
- The first sentence names who acted.
- The passive in the second sentence keeps attention on the values.
What it shows: A report can combine voices while maintaining a consistent time frame.
Common mistakes
Draft (not correct): The outlet flow is 150.
Revision: The outlet mass flow is 150 kg/h.
The quantity and unit make the number meaningful.
Draft (not correct): A past-tense method is wrong because scientific writing must be present passive.
Revision: Use the tense and voice that fit the actual purpose and reporting convention.
Completed work and a general process are different communicative situations.
Keep in mind
- Follow the process in a logical order.
- State quantities with units and a basis.
- Keep assumptions and observed facts distinct.
Foundation lesson; not an official syllabus, accredited CEFR placement, or score prediction.
Next: Develop a position in a complete essay. State a qualified position, develop reasons and respond to a relevant limitation.
Original Bayt Al-Fuad teaching text and invented examples; not publisher lesson text. Aligned with: English Grammar — Rebekah Hendershot · English Composition — Joel Gonzaga · University Success level differentiation. Sources and credits.