Quick Answer
In Vietnamese, thì is primarily a topic marker (meaning 'as for' or 'then' in conditional sentences), while mà is a relative pronoun (meaning 'that/which/who') or used to show contrast and emphasis.
Comparison Table
| Feature | thì | mà |
|---|---|---|
| Primary Role | Topic Marker / Conditional Link | Relative Pronoun / Contrastive Link |
| English Equivalent | As for, then, if... then | That, which, who, but/yet |
| Hán-Việt Connection | 时 (Shí) - meaning time/period | No direct Hán-Việt equivalent |
| Example | Tôi thì thích ăn phở. As for me, I like eating pho. | Cái áo mà tôi mua rất đẹp. The shirt that I bought is very beautiful. |
Detailed Explanation
The word thì acts as a bridge between a topic and a comment. It creates a slight pause, allowing the speaker to define what they are talking about before providing information. It is also the essential second half of the 'Nếu... thì' (If... then) structure. In Northern dialects, 'thì' is often used to emphasize a contrast between two subjects (e.g., 'I like this, but he likes that').
The word mà is more versatile but primarily functions as a relative pronoun to link a noun to a descriptive clause. Unlike 'thì', which marks a topic, 'mà' connects information. Furthermore, 'mà' expresses a sense of 'but' or 'yet' when something happens contrary to expectation. It can also be found in structures expressing causes ('Chính vì... mà...') or at the end of sentences for insistent emphasis.
Example Pairs
Nếu ngày mai trời nắng thì chúng ta đi chơi.
If it is sunny tomorrow, then we will go out.
Trời nắng mà anh ấy vẫn mặc áo khoác.
It's sunny, yet he is still wearing a jacket.
Quyển sách này thì rất hay.
As for this book, it is very good.
Quyển sách mà bạn cho tôi mượn rất hay.
The book that you lent me is very good.
Cam thì ngọt, chanh thì chua.
As for oranges, they are sweet; as for lemons, they are sour.
Quả cam này trông xanh mà lại rất ngọt.
This orange looks green, but it's actually very sweet.
Ăn thì ăn nhanh lên!
If you're going to eat, eat quickly!
Đã bảo là không ăn mà!
I already told you I'm not eating (insistent emphasis)!
Học thì mệt nhưng vui.
Studying (as a topic) is tiring but fun.
Học mà không hành thì không hiệu quả.
Studying without practicing is not effective.
Tôi thì không biết chuyện đó.
As for me, I don't know about that matter.
Làm sao mà tôi biết được?
How could I possibly know?
Tới nơi thì gọi cho tôi nhé.
When you arrive (then), call me okay?
Nơi mà tôi sinh ra rất yên bình.
The place where I was born is very peaceful.
Giàu thì có giàu, nhưng không hạnh phúc.
Rich they may be, but they aren't happy.
Giàu mà keo kiệt quá.
Rich yet so stingy.
Common Patterns
Nếu... thì...: The standard 'If... then...' conditional construction.
Danh từ + mà + Mệnh đề: The relative clause pattern (The noun that/which...).
Sao mà... thế/vậy?: An emphatic way to ask 'Why/How come...?' expressing surprise.
Chính vì... mà...: 'It is precisely because... that...' used to emphasize a cause-effect relationship.
Common Mistakes
Mistake 1 — Using 'thì' as a Relative Pronoun
Learners often use 'thì' to mean 'that' or 'which' because they think it links parts of a sentence generally.
❌ Đây là người thì tôi yêu.
✅ Đây là người mà tôi yêu.
Why it's wrong: 'Thì' is a topic marker or conditional link. To describe a person with an action clause (the person whom I love), you must use the relative pronoun 'mà'.
Mistake 2 — Forgetting 'thì' in Conditional Sentences
English speakers often omit 'then' in 'if-then' sentences, but in Vietnamese, 'thì' is almost always required for natural flow.
❌ Nếu bạn rảnh, đi cà phê với tôi.
✅ Nếu bạn rảnh thì đi cà phê với tôi.
Why it's wrong: While understandable, omitting 'thì' makes the sentence sound choppy. 'Thì' acts as the logical connector for the result clause.
Mistake 3 — Using 'mà' for Simple Topic Introduction
When introducing a subject to talk about it, 'mà' is too strong because it implies a connection or contrast that might not exist.
❌ Tiếng Việt mà khó quá.
✅ Tiếng Việt thì khó quá.
Why it's wrong: 'Tiếng Việt mà khó quá' implies 'Vietnamese is difficult (despite something else)' or 'Why is Vietnamese so difficult?'. For a simple statement of opinion about the topic, use 'thì'.
Quick Quiz
Fill in the blank with thì or mà:
Nếu anh không đến _____ tôi sẽ đi một mình.
Hint: This is a conditional sentence (If... then).
Answer
Correct answer: thì. Full sentence: Nếu anh không đến thì tôi sẽ đi một mình. (If you don't come, then I will go alone.)
Fill in the blank with thì or mà:
Món ăn _____ mẹ tôi nấu là ngon nhất.
Hint: This is a relative clause describing 'the dish'.
Answer
Correct answer: mà. Full sentence: Món ăn mà mẹ tôi nấu là ngon nhất. (The dish that my mother cooks is the best.)
Fill in the blank with thì or mà:
Anh ấy hứa rồi _____ vẫn không làm.
Hint: This expresses a contrast or a result contrary to expectation.
Answer
Correct answer: mà. Full sentence: Anh ấy hứa rồi mà vẫn không làm. (He promised, yet he still didn't do it.)