Vietnamese Duration and Timing

The short version

Use bao lâu, từ khi, đến khi, and trong to talk about time length.

Pattern box

mất bao lâu / từ + time + đến + time.

English trap

Do not confuse time point with duration.

Right vs wrong examples

Instead of this	Say this	Why
Copy the English structure word by word	Tôi muốn nói về lịch hẹn	Use the Vietnamese pattern as a ready-made chunk.
Add extra grammar words because English needs them	Theo tôi thì điều này quan trọng	Vietnamese often stays shorter than English.
Study the rule without a real situation	Tôi nghĩ vậy	Attach the rule to a cafe, taxi, hotel, market, or work sentence.

Core examples

Vietnamese	English	Practice note
Tôi muốn nói về lịch hẹn	I want to talk about appointments	Start a appointments conversation.
Theo tôi thì điều này quan trọng	In my opinion, this is important	Use for simple opinions.
Tôi nghĩ vậy	I think so	A soft agreement phrase.
Tôi không chắc lắm	I am not very sure	Useful when you need time or clarity.
Bạn có thể nói rõ hơn không?	Can you explain more clearly?	Ask for clarification.
Lý do là gì?	What is the reason?	Ask why without a long sentence.
Tôi cần thêm thời gian	I need more time	Use before deciding or answering.
Chúng ta làm thế nào?	How should we do it?	Useful for planning.
Có vấn đề gì không?	Is there any problem?	Check if something is wrong.
Tôi muốn giải quyết việc này	I want to solve this	Useful in service and work situations.
Mình nói chuyện sau nhé	Let us talk later	A soft delay phrase.
Gửi cho tôi chi tiết nhé	Please send me the details	Good follow-up phrase.

How to use it in real sentences

Use the examples as sentence patterns, not isolated vocabulary. Say the whole line first, then replace one small part such as the person, time, object, or place.

Substitution drill

Base sentence	Change this	New sentence
Tôi muốn nói về lịch hẹn	change the person or topic	Theo tôi thì điều này quan trọng
Theo tôi thì điều này quan trọng	change the time, place, or object	Tôi nghĩ vậy
Tôi nghĩ vậy	say it as a real request or answer	Tôi không chắc lắm

Real situation

Use this sentence building grammar when a real conversation forces you to speak quickly. Pick one sentence from the examples, imagine the situation, then change only one detail so the grammar becomes usable instead of abstract.

Southern Vietnamese note

Southern Vietnamese often prefers practical, context-rich examples. Learn the pattern through a line you might actually say.

Practice drill

1. Read each Vietnamese sentence aloud.
2. Replace one noun or time word.
3. Listen to the slow audio, then say the new sentence twice.
4. Cover the English and recall the Vietnamese from the situation.
5. Save the examples you would actually use this week.

Common mistake

Do not confuse time point with duration.

Next step

After this page, open the related practice or continue to the next grammar lesson: expressing-ability-limits.