thì is used to mark what the speaker is talking about first, before saying something about it. It helps organize the sentence by separating the topic (what is already known or assumed) from the comment (what the speaker wants to say about it).
thì does not add new meaning by itself. Its function is to guide the listener: “About this thing/person/situation — here is my comment.”
Because of this, thì is extremely common in spoken Vietnamese.
[1] – Còn tôi thì không đồng ý. As for me, I don’t agree.
→ tôi is the topic. thì signals that the speaker is now giving an opinion about it.
Without thì, the sentence is still grammatical, but less clear in contrast.
[2] – Anh thì thích cà phê, còn tôi thì thích trà. He likes coffee, while I like tea.
→ thì clearly separates and contrasts the two topics. This use is very common in comparisons.
[3] – Còn chuyện hôm qua thì để mai nói. As for yesterday’s matter, let’s talk about it tomorrow.
→ The topic (chuyện hôm qua) is already known in the conversation. thì helps bring it back into focus.
[4] – Trời mưa thì tôi ở nhà. If it rains, I stay at home.
→ thì marks a natural or expected response to a situation. The sentence sounds calm and conversational.
[5] – Biết thì biết, nhưng không chắc lắm. I do know, but I’m not very sure.
→ thì makes the sentence sound less abrupt and more natural in speech.
thì vs mà
– thì: organizes information, sets up topic → comment – mà: often adds contrast, explanation, or emotion
[6a] – Tôi thì không thích phim đó. As for me, I don’t like that movie.
[6b] – Tôi không thích phim đó mà. I don’t like that movie (with emphasis or attitude).
thì vs là
– thì: separates topic and comment – là: links or identifies
[7a] – Còn anh thì sao? And what about you?
[7b] – Anh là ai? Who are you?
• thì usually appears after the topic, not at the end of the sentence.
Correct: ✓ Tôi thì thích ở nhà.
Incorrect: ✗ Tôi thích ở nhà thì.
• thì is very often optional. Removing it does not usually change the basic meaning, but it changes how natural and organized the sentence sounds.
Compare: – Tôi không đi. – Tôi thì không đi.
The second sounds more conversational and contrastive.
• thì is extremely common in spoken Vietnamese and informal writing.
• Do not translate thì directly into English. Its function is structural and pragmatic, not lexical.
• Topic + thì + comment
– Tôi thì không biết. I don’t know.
– Cái này thì dễ. This one is easy.
• Còn + topic + thì…
– Còn anh thì sao? What about you?
• Situation + thì + result
– Có tiền thì mua. If you have money, then buy it.