The Estimation Problem Nobody Talks About
You know the story. The Scrum Master asks: “How long will this task take?” And you say something like:
“Uh… I think… maybe… 2 days? Or 3? It depend on the requirement.”
The room goes quiet. Your manager writes something down. You feel your confidence drop.
The problem isn’t your technical skill — it’s the language. Vietnamese developers often know the answer but lack the exact English phrases to sound confident, structured, and professional during sprint planning or estimation sessions.
This post gives you the exact words to use, so you can estimate like a senior engineer — even when you’re not 100% sure.
Why Estimation Language Matters
In international teams, how you say something matters as much as what you say.
Compare:
- ❌ “I don’t know, maybe 3 days, it depends.”
- ✅ “Based on the scope, I’d estimate 3 days, assuming the API contract is finalized. If there are changes, it could go up to 5.”
Same uncertainty. Completely different impression.
The second version tells your team: you’ve thought it through, you know the risks, and you’re tracking dependencies. That’s what senior engineers sound like.
🗣️ Key Phrases to Say Out Loud
Practice these until they feel natural. Say them loud — not just read them silently.
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“Based on the current scope, I’d estimate…” /beɪst ɒn ðə ˈkɜːrənt skəʊp, aɪd ˈestɪmeɪt/ Use this to open your estimate confidently.
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“That depends on whether we get clarity on…” /ðæt dɪˈpendz ɒn ˈweðər wi ɡet ˈklærɪti ɒn/ Use this to flag a blocker without sounding unsure.
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“I’m comfortable committing to X, but I’d flag Y as a risk.” /aɪm ˈkʌmftəbəl kəˈmɪtɪŋ tuː… bʌt aɪd flæɡ… æz ə rɪsk/ This is the phrase of confident engineers everywhere.
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“My rough estimate is… but let me validate that after a quick spike.” /maɪ rʌf ˈestɪmət ɪz… bʌt let mi ˈvælɪdeɪt ðæt ˈɑːftər ə kwɪk spaɪk/ Perfect when the task is technically unclear.
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“This ticket has some unknowns — I’d size it as a Medium or Large.” /ðɪs ˈtɪkɪt hæz səm ʌnˈnəʊnz — aɪd saɪz ɪt æz ə ˈmiːdiəm ɔː lɑːdʒ/
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“Can we timebox the investigation to one day and revisit?” /kæn wi ˈtaɪmbɒks ðə ɪnˌvestɪˈɡeɪʃən tuː wʌn deɪ ænd ˌriːˈvɪzɪt/
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“I want to push back on that estimate — I think we’re underestimating the integration work.” /aɪ wɒnt tə pʊʃ bæk ɒn ðæt ˈestɪmət — aɪ θɪŋk wiːr ˌʌndərˈestɪmeɪtɪŋ ðə ˌɪntɪˈɡreɪʃən wɜːk/
📚 Vocabulary
1. Estimate (noun & verb) — /ˈestɪmət/ (noun) / /ˈestɪmeɪt/ (verb)
“My estimate is 3 days.” vs. “I estimate this will take 3 days.” Note: The noun and verb are pronounced differently! This trips up many learners.
2. Scope creep — /skəʊp kriːp/
“We need to watch for scope creep — this ticket is already growing.” Meaning: When a task gradually expands beyond its original boundaries.
3. Spike — /spaɪk/
“Let’s do a one-day spike to understand the third-party API before estimating.” Meaning: A short, time-boxed investigation to reduce uncertainty.
4. Timebox — /ˈtaɪmbɒks/
“Timebox the research to 4 hours max.” Meaning: Set a strict time limit on an activity.
5. Blocker — /ˈblɒkər/
“The main blocker is waiting for design approval.” Meaning: Something that prevents progress on a task.
6. Velocity — /vəˈlɒsɪti/
“Our velocity last sprint was 42 points — let’s plan accordingly.” Meaning: The amount of work a team completes per sprint, measured in story points.
7. Dependency — /dɪˈpendənsi/
“This task has a dependency on the auth service being deployed first.” Meaning: When one task requires another to be completed first.
🎯 Practice Now
Scenario: Sprint Planning with Your Scrum Master
Read this dialogue out loud. Play both roles. Focus on sounding calm and confident, not robotic.
Scrum Master: “Okay, ticket VIC-234 — Add export to CSV for the report page. What’s your estimate, Thuan?”
You: “Let me think for a second. The UI part is straightforward — maybe a day. But the data layer depends on how many filters we need to support. If it’s just the current filters, I’d say 3 days total. If we’re adding new filter combinations, push that to 5.”
Scrum Master: “Let’s scope it to current filters only for this sprint.”
You: “Perfect. Then I’m comfortable committing to 3 days. I’ll flag one risk though — if the report query is slow on large datasets, we might need to add async export. Can I do a quick 2-hour spike on Day 1 to validate performance?”
Scrum Master: “Sure, makes sense.”
You: “Great. I’ll update the ticket with findings before EOD Monday.”
Repeat this 3 times. Then record yourself once and listen back. Notice:
- Did you pause confidently, or rush?
- Did you say “it depend” (wrong) or “it depends” (correct)?
- Did your voice go up at the end (uncertain) or stay flat/down (confident)?
Quick Fill-in-the-Blank Drill
Complete these sentences naturally:
- “Based on the _______, I’d estimate this takes about 4 days.”
- “I’m comfortable committing to this, but I’d flag _______ as a risk.”
- “Can we _______ the investigation to half a day and then reassess?”
- “This ticket has a _______ on the payment service — we can’t start until that’s done.”
- “I want to push back — I think we’re _______ the testing effort.”
(Answers: scope / the API integration / timebox / dependency / underestimating)
Real Tip: The “3-Part Estimate” Formula
When you don’t know, use this structure:
“My estimate is [X], assuming [condition]. If [risk happens], it could be [Y]. I’ll know more after [action].”
Example:
“My estimate is 3 days, assuming the designs are final. If there are major revisions, it could go to 5. I’ll know more after the design review on Tuesday.”
This single formula makes you sound senior in any sprint planning, in any company, in any country.
Wrapping Up
Estimation is a skill — and so is talking about estimation in English. The goal isn’t to sound perfect; it’s to sound clear, structured, and trustworthy.
Start small: in your next sprint planning, use just one of the phrases above. Then add another next sprint. In 4 weeks, you’ll sound like a completely different engineer — not because you changed your skills, but because you found the words for what you already know.
Now close this tab and practice that dialogue one more time. Out loud.