gì vs nào — What vs Which

Quick Answer

Use gì (what) for open-ended questions about something completely unknown — no options are given or implied. Use [nào (which) when you are selecting from a known or implied group of options. Think of it this way: gì opens up all possibilities, while nào narrows down to a specific choice from a set.

Comparison Table

Detailed Explanation

gì — What

gì is an open-ended question word meaning what. Use it when you have no idea what the answer will be and no specific options are implied. In Vietnamese, gì typically comes at the end of a sentence or directly after a verb.

Common structures with gì:

• [Noun] là gì? — What is [noun]?
• [Subject] [verb] gì? — What does [subject] [verb]?
• gì đó — something (an unspecified thing)
• không có gì — nothing; also used as you're welcome

Note on Southern Vietnamese: In the South, speakers commonly say chi instead of gì. For example, the standard question Làm gì vậy? (What are you doing?) becomes Làm chi vậy? in Southern speech. Both are understood nationwide, but gì is the standard written and formal form.

nào — Which

nào means which and is used when selecting from a known or implied group of options. It always follows a noun — you cannot use nào alone without a noun in front of it. This is the key grammar rule to remember.

Common structures with nào:

• [Noun] nào? — Which [noun]?
• [Subject] [verb] [noun] nào? — Which [noun] does [subject] [verb]?
• hôm nào — which day / someday
• lúc nào — which time / whenever
• [noun] nào đó — some [noun] (an unspecified one from a group)

Note for Japanese and Chinese learners: The gì vs nào distinction closely mirrors Japanese どんな (donna) vs どの (dono/どれ dore), and Chinese 什么 (shénme) vs 哪个 (nǎge). If you already know these pairs, the Vietnamese pattern will feel immediately familiar. Korean learners can think of 무엇 (mueot) vs 어느 것 (eoneu geot).

Example Pairs

Pair 1 — Asking about food

Pair 2 — Asking about a drink

Pair 3 — Identifying an unknown object

Pair 4 — Color preference

Pair 5 — Asking about studies

Pair 6 — Asking about a name

Pair 7 — Asking about language

Pair 8 — Asking about a day

Common Patterns

Fixed patterns with gì

Fixed patterns with nào

Common Mistakes

Mistake 1 — Using gì when choosing from known options

When specific options are already listed, you must use nào to ask someone to choose between them. Using gì here ignores the stated context and sounds like a completely open question.

❌ Màu đỏ hay màu xanh, bạn thích màu gì?

✅ Màu đỏ hay màu xanh, bạn thích màu nào?

Two specific colors are already stated before the question, so the listener is choosing between them — use nào. Using gì would mean you are asking about color preference with no options at all, which contradicts the setup of the sentence.

Mistake 2 — Using nào without a noun before it

nào must always follow a noun. It cannot stand alone as a question word the way gì can. If you have no noun to attach it to, use gì instead, or add a classifier such as cái, loại, or món.

❌ Bạn muốn nào?

✅ Bạn muốn cái nào? (Which one do you want?)

✅ Bạn muốn gì? (What do you want?)

Without a noun or classifier, nào is grammatically incomplete. Always pair it with a noun: cái nào, loại nào, món nào, and so on.

Mistake 3 — Using nào for a completely unknown thing

If you genuinely have no idea what something is — no category, no group — use gì. Using nào implies you already know the category and are simply choosing one item from within it.

❌ Đây là cái nào? (when you have no idea what the object even is)

✅ Đây là cái gì? (What is this?)

nào presupposes a known group, such as which of these three books. If the object is a mystery to you entirely, use gì to ask what it is before asking which one it is.

Mistake 4 — Forgetting the noun before nào in time phrases

When asking about time using nào, you must always include the time noun. Dropping the noun makes the sentence incomplete and ungrammatical in Vietnamese.

❌ Bạn đến nào?

✅ Bạn đến ngày nào? (Which day are you coming?)

✅ Bạn đến lúc nào? (What time are you coming?)

Choose the right time noun: ngày (day), hôm (day in context), lúc (moment/time), tuần (week), tháng (month). Always state the noun first, then follow with nào.

Mistake 5 — Confusing gì đó and nào đó

Both gì đó and nào đó mean something or some, but the distinction mirrors gì vs nào. Use gì đó for something from anywhere; use nào đó for some one from a specific known group.

❌ Tôi muốn ăn gì đó trong thực đơn này.

✅ Tôi muốn ăn món nào đó trong thực đơn này.

Because the menu (thực đơn) is a defined set of options, you are picking from within that set — use nào đó. Use gì đó when there is no specific group: Tôi muốn ăn gì đó. (I want to eat something — anything.)

Related Grammar Points

• nào — Which? in Vietnamese (Grammar A1)
• bao nhiêu vs mấy — How Many (Large vs Small) (Comparison A1)
• là vs Zero Copula — When to Use 'là' (Comparison A1)
• không vs chưa — Two Types of Negation (Comparison A1)
• đã vs rồi — Past Tense vs Completion (Comparison A1)
• cái vs con — Object vs Animal Classifiers (Comparison A1)

Quick Quiz

Fill in the blank with gì or nào:

Question 1: Bạn đang ăn _____?

Hint: There are no options given — you have no idea what the person is eating.

Question 2: Phở hay bún bò Huế, bạn thích món _____?

Hint: Two specific dishes are listed before the blank — you are choosing between them.

Question 3: Tên của con mèo đó là _____?

Hint: You don't know the cat's name at all — it is a completely open question with no options given.