Defining and Explaining in Vietnamese

In Brief

Use X là gì? to ask what X is, (có) nghĩa là to state what a word, sign, or situation means, tức là to restate or clarify, and gọi là to give something a name. All four patterns help explain ideas, but they are not interchangeable: one asks for a definition, one gives meaning, one reformulates, and one labels.

Overview

At B1, Vietnamese learners begin doing more than identifying people and things. You need to ask what an unfamiliar idea is, explain vocabulary, draw out the meaning of a situation, and repair a misunderstanding. These skills appear in everyday conversation as well as lessons, presentations, instructions, and academic writing.

The patterns in this article build on là, the linking word already familiar from sentences such as Lan là bác sĩ (“Lan is a doctor”). In a definition, là connects a topic with information that identifies or describes it. Vietnamese does not change the form of là for person, number, or tense, so the main challenge is choosing the right explanatory pattern and arranging its parts naturally.

The four core expressions correspond only roughly to English “what is,” “mean,” “that is,” and “call.” English habits can therefore mislead you. In particular, Vietnamese often leaves the subject unspoken when the context supplies it, and tức là can introduce a conclusion rather than a dictionary meaning.

How It Works

Asking what something is: X là gì?

The question word gì means “what.” To ask for the identity, nature, or definition of X, put the topic first and gì at the end:

X + là + gì?

• Phở là gì? — “What is pho?”
• Trí tuệ nhân tạo là gì? — “What is artificial intelligence?”
• Mục đích của cuộc họp là gì? — “What is the purpose of the meeting?”

This final position is important. Unlike English, Vietnamese does not normally move “what” to the beginning in this pattern. X can be a concrete thing, a word, an abstract concept, or a longer noun phrase (a group of words functioning as the name of something).

When you specifically want the meaning of a word or expression, two questions are especially useful:

• X nghĩa là gì? — “What does X mean?”
• Nghĩa của X là gì? — “What is the meaning of X?”

The first is usually shorter and more conversational. The second explicitly makes nghĩa (“meaning”) the topic and fits careful explanations well.

Giving a meaning: (có) nghĩa là

Use nghĩa là or có nghĩa là before the meaning or interpretation:

X + (có) nghĩa là + Y

• “Miễn phí” có nghĩa là không phải trả tiền. — “Miễn phí means you do not have to pay.”
• Đèn đỏ nghĩa là phải dừng lại. — “A red light means you must stop.”

Here có literally contributes the idea of “having”: X “has the meaning that” Y. Both versions are common. Có nghĩa là is often a little fuller and especially clear when the expression being defined is stated. Nghĩa là is also natural and is frequently used after a topic or by itself when the context already tells listeners what is being interpreted:

• Nghĩa là bạn đồng ý. — “It means you agree.”

Y may be a word, a phrase, or a complete clause (a group of words expressing a situation, usually with its own subject or understood subject). This construction can explain not only vocabulary but also signs, actions, and consequences.

Restating or drawing a conclusion: tức là

Use tức là when Y reformulates, makes explicit, or follows from what has just been said:

statement + tức là + clearer statement or consequence

• Ngày mai cửa hàng nghỉ, tức là chúng ta phải đi hôm nay. — “The shop is closed tomorrow, so that means we have to go today.”
• Anh ấy là anh họ của tôi, tức là con của bác tôi. — “He is my cousin—that is, my aunt’s or uncle’s son.”

Depending on context, natural English translations include “that is,” “in other words,” “which means,” and “so.” Tức là is a discourse connector (an expression that shows how one part of the message relates to another), not merely a dictionary verb meaning “mean.” It often stands at the beginning of a response:

• Tức là phải làm lại. — “In other words, we have to do it again.”
• Tức là anh không đến à? — “So you’re not coming?”

The second example checks an inference. The final particle à turns the speaker’s interpretation into a confirmation question.

Naming something: gọi là

Use gọi là when the point is the name or label assigned to something. Several sentence frames are possible:

Pattern	Main focus	Example
X gọi là Y	everyday naming	Cái này gọi là áo dài.
Người ta gọi X là Y	what people call X	Người ta gọi món này là phở cuốn.
X được gọi là Y	the name given to X	Hiện tượng này được gọi là biến đổi khí hậu.
Gọi X là Y	naming X as Y	Ta gọi số đó là x.

In người ta gọi X là Y, người ta means “people” or an unspecified “they.” The verb gọi means “call,” X is the thing being named, and Y is its label. Do not omit X if doing so would leave the listener unsure what is being named.

Được gọi là is a passive pattern: the subject receives the name rather than actively giving it. It is common in definitions and formal explanations. Here được helps present X as “being called” Y; it does not necessarily express a benefit, even though được has that sense in many other sentences.

Choosing among the four patterns

Communicative goal	Use	Typical English equivalent
Ask for identity or a definition	X là gì?	What is X?
Ask what an expression means	X nghĩa là gì?	What does X mean?
State meaning or interpretation	X (có) nghĩa là Y	X means Y
Clarify or infer from a statement	tức là Y	that is / in other words / so
Supply a name or technical label	(được) gọi là Y	is called Y

A useful distinction is meaning versus name. “Nhanh” có nghĩa là “fast” explains meaning. Món này gọi là bánh xèo supplies the dish’s name. A definition can contain both: Bánh xèo là một loại bánh mặn; món này được gọi là “bánh xèo” vì khi đổ bột vào chảo có tiếng xèo. (“Bánh xèo is a kind of savory pancake; the dish is called bánh xèo because the batter sizzles when poured into the pan.”)

Examples in Context

Vietnamese	English	Note
Phở là gì?	What is pho?	Asks for a basic definition.
Văn hóa là gì?	What is culture?	Asks about an abstract concept.
Mục tiêu của dự án này là gì?	What is the goal of this project?	The whole noun phrase is the topic.
“Bền vững” nghĩa là gì?	What does bền vững mean?	Asks about a word’s meaning.
Nghĩa của từ này là gì?	What is the meaning of this word?	A fuller, explicit question.
“Độc lập” có nghĩa là không phụ thuộc vào người khác.	Độc lập means not depending on others.	Gives a lexical definition.
Im lặng không phải lúc nào cũng có nghĩa là đồng ý.	Silence does not always mean agreement.	Interprets behavior; không phải lúc nào cũng means “not always.”
Đèn này nhấp nháy nghĩa là pin sắp hết.	This light flashing means the battery is nearly empty.	Explains what a sign indicates.
Nghĩa là bạn đồng ý, đúng không?	It means you agree, right?	The interpreted topic is understood.
Chuyến cuối đã đi rồi, tức là chúng ta phải đợi đến sáng.	The last service has left, so we have to wait until morning.	Draws a practical conclusion.
Tôi nói “tuần sau”, tức là sau thứ Hai tới.	I said “next week,” that is, after this coming Monday.	Clarifies an earlier phrase.
Tức là anh không cần bản in nữa à?	So you no longer need the printed copy?	Checks the listener’s intended meaning.
Cái này gọi là áo dài.	This is called áo dài.	Gives an everyday name.
Người Việt gọi loại quả này là thanh long.	Vietnamese people call this fruit thanh long (dragon fruit).	The people assigning the name are stated.
Quá trình này được gọi là quang hợp.	This process is called photosynthesis.	Passive naming in an explanatory register.

Common Mistakes

Putting gì where English puts “what”

• Wrong: Gì là phở?
• Right: Phở là gì?
• Why: In this Vietnamese question frame, the topic comes first and gì stays after là. Do not copy English question order.

Using là gì for the meaning of a word when the question is unclear

• Less clear: “Tiết kiệm” là gì?
• Clearer for vocabulary: “Tiết kiệm” nghĩa là gì?
• Why: Là gì? can ask what the concept itself is, while nghĩa là gì? directly asks what the expression means. Both may work in context, but the second removes ambiguity in a vocabulary question.

Treating tức là as a label

• Wrong: Món này tức là bánh xèo.
• Right: Món này gọi là bánh xèo.
• Why: Tức là clarifies or draws a conclusion; gọi là supplies a name. Use the pattern that matches your communicative purpose.

Copying the English “call” pattern too literally

• Wrong: Người ta gọi là món này bánh xèo.
• Right: Người ta gọi món này là bánh xèo.
• Why: In the active naming frame, place the thing being named between gọi and là: gọi + X + là + Y.

Omitting the link before a definition

• Wrong: “Miễn phí” nghĩa không phải trả tiền.
• Right: “Miễn phí” nghĩa là không phải trả tiền.
• Why: The fixed explanatory expression is nghĩa là or có nghĩa là. Keep là before the explanation.

Assuming được always means “allowed to” or “beneficially”

• Wrong interpretation: Thuật ngữ này được gọi là “từ láy” = “This term is allowed to call itself từ láy.”
• Right interpretation: “This term is called từ láy.”
• Why: In được gọi là, được participates in a passive construction. Context, not a single fixed English translation, determines its role.

Usage Notes

Là gì? is neutral and works in conversation, teaching, interviews, and headings such as Học máy là gì? (“What is machine learning?”). With people, a bare question such as Anh là gì? can sound as though you are asking about someone’s role or status and may be abrupt. Ask the intended detail instead: Anh làm nghề gì? (“What do you do?”) or Vai trò của anh là gì? (“What is your role?”).

Nghĩa là and có nghĩa là occur in both speech and writing. In spontaneous speech, the topic is often recoverable and omitted: Nghĩa là sao? is a common request roughly meaning “What does that mean?” or “How so?” Sao here asks for an explanation of the situation, often with a more conversational or surprised tone than X nghĩa là gì?

Tức là is very frequent in speech because speakers use it to reformulate while thinking. Repeating it too often, however, can sound hesitant. In careful formal prose, alternatives may better show the exact relationship, such as nói cách khác (“in other words”), cụ thể là (“specifically”), or a precise cause-and-result connector. Tức là remains perfectly acceptable when genuine restatement is intended.

Được gọi là suits textbooks, reports, and technical definitions because it focuses on the term rather than whoever invented or uses it. Người ta gọi... là... is more personal and often more natural when describing ordinary naming customs. In informal conversation, X gọi là Y is also heard, especially with demonstratives such as cái này (“this thing”).

Vietnamese may leave out a subject or topic that is obvious from context. English generally needs an explicit “it” in “It means...”; Vietnamese can simply say Nghĩa là... or Tức là.... Add the topic when a standalone sentence might otherwise be ambiguous.

Beyond the Basics / Advanced Use

The boundary between definition, interpretation, and inference is sometimes pragmatic—that is, determined by what the speaker is doing in context rather than by sentence form alone. Compare:

• Dấu này có nghĩa là “cấm vào”. — The sign has the established meaning “no entry.”
• Anh ấy không trả lời, tức là anh ấy chưa quyết định. — The speaker infers or summarizes: “He did not answer, so that means he has not decided.”

The second conclusion may be the speaker’s interpretation, not an objective definition. For that reason, tức là can sound too strong if the evidence is uncertain. Soften the claim with expressions such as có lẽ (“perhaps”) or frame it as a check: Tức là anh ấy chưa quyết định à? (“So he hasn’t decided?”).

Definitions in formal Vietnamese often combine a term with a category and then a distinguishing feature:

X + là + category + that/which + distinguishing information

• Tam giác là hình có ba cạnh. — “A triangle is a shape with three sides.”
• Tình nguyện viên là người tự nguyện làm việc để giúp đỡ cộng đồng. — “A volunteer is a person who willingly works to help the community.”

Vietnamese does not require an article equivalent to English “a” in these generic definitions. English speakers sometimes add một mechanically because the translation has “a.” Một is possible when the sense truly emphasizes “one” or “a certain,” but it is not required simply to mark an indefinite category.

Quotation marks can help distinguish a word from the thing it refers to: “Bàn” có nghĩa là “table” discusses the word bàn, while Bàn là đồ nội thất... defines a table as an object. In speech, context and intonation usually make this distinction; in writing, quotation marks improve precision.

Finally, gọi là has uses beyond neutral naming. In some contexts it can introduce a classification or an evaluation: Như thế mới gọi là công bằng (“Now that is what you call fair”). It may also appear in the expression gọi là, meaning something like “just as a token” or “so to speak” in certain sentences. These idiomatic extensions depend heavily on context; at B1, master the literal naming patterns first.

Practice Tips

1. Sort examples by purpose. Make four headings—question, meaning, clarification, and name—and place new sentences under là gì, nghĩa là, tức là, or gọi là. This trains choice, not just memorization.
2. Define familiar things in simple Vietnamese. Try a food, an occupation, and an abstract word: Phở là..., Giáo viên là người..., “Kiên nhẫn” có nghĩa là.... Keep each definition to one clear sentence before adding detail.
3. Listen for repairs in conversation. When a speaker says tức là, pause and identify whether the next phrase restates, specifies, or concludes. Then paraphrase the same idea with nói cách khác if that meaning fits.

Related Concepts

• Prerequisite: Là (to be) — the basic linking pattern used to identify and classify people, things, and ideas.