Quick Answer
Both ẩn dụ (metaphor) and hoán dụ (metonymy) are figures of speech that rename one thing using a different word, but they operate on opposite principles. Ẩn dụ works through similarity — you call X by the name of Y because X and Y share a quality or appearance. Hoán dụ works through association — you call X by the name of Y because X and Y are closely connected in reality, not because they resemble each other.
The key diagnostic test: ask yourself whether the link between the two things is a shared quality (ẩn dụ) or a real-world factual connection such as part-to-whole, place-to-institution, or attribute-to-person (hoán dụ). Both devices compress meaning and add vividness, but they do so through fundamentally different logical operations.
Comparison Table
| Feature | Ẩn dụ (Metaphor) | Hoán dụ (Metonymy) |
|---|---|---|
| Basis of substitution | Similarity (tương đồng) | Association / Contiguity (tương cận) |
| Core question | "How are these two things alike?" | "How are these two things connected in real life?" |
| Logical structure | A resembles B in some quality → call A "B" | A is part of, contains, or is linked to B → call A "B" |
| Hán-Việt breakdown | 隱喻 — ẩn (hidden) + dụ (comparison): a hidden comparison | 換喻 — hoán (to swap/replace) + dụ (comparison): a replacement by association |
| Japanese / Chinese equivalent | JA: 隠喩 (in'yu) / ZH: 暗喻 (ànyù) | JA: 換喩 (kan'yu) / ZH: 換喻 (huànyù) |
| Common subtypes | Form, quality, action, synesthesia (chuyển đổi cảm giác) | Part-for-whole, container-for-contents, attribute-for-person, author-for-work, place-for-institution |
| Example sentence | Mắt em là hai vì sao sáng. | Chiếc áo số 10 ghi bàn quyết định. |
| Why it works | Eyes and stars share the quality of brightness and beauty | The jersey number is the real-world identifier for the player wearing it |
Detailed Explanation
Ẩn dụ — Metaphor
The compound ẩn dụ (隱喻) literally means "hidden comparison." Unlike a simile (so sánh), which uses explicit linking words like như (like/as) or tựa như (resembling), a metaphor states the equation directly: A is B, not A is like B. This directness makes the image more forceful and more memorable in literary Vietnamese.
Vietnamese linguistics traditionally recognizes four subtypes of ẩn dụ:
Ẩn dụ hình thức (Form/Appearance): comparison based on visual or structural resemblance — e.g., calling someone's eyes "stars" because both sparkle.Ẩn dụ phẩm chất (Quality): comparison based on a shared abstract quality — e.g., calling a kind person "a flower" because flowers are beautiful and gentle.Ẩn dụ cách thức (Manner/Action): comparison based on how something is performed — e.g., describing the way knowledge spreads as "light flooding a dark room."Ẩn dụ chuyển đổi cảm giác (Synesthesia): crossing sensory channels — e.g., describing a voice as "sweet" (ngọt ngào) maps taste onto sound, or calling colors "loud" (ồn ào) maps sound onto sight.
Ẩn dụ appears extensively in Vietnamese poetry, proverbs, folk songs (ca dao), and formal literary prose. On NLTV C1–C2 examinations, candidates are expected to identify the subtype of metaphor and explain the basis of comparison.
Hoán dụ — Metonymy
The compound hoán dụ (換喻) literally means "replacement comparison." It substitutes one word for another based on a real, factual connection between the two things — not a perceived similarity. The audience must already know the associative link; if they do not share that cultural knowledge, the metonymy fails to communicate.
Vietnamese grammar textbooks classify hoán dụ into four standard subtypes:
Bộ phận thay toàn thể (Part for Whole): a part of something stands for the entire thing — e.g., bàn tay (hand) used to mean "worker" or "human effort."Vật chứa thay vật bị chứa (Container for Contents): e.g., cả làng (the whole village) used to mean "all the people living in the village."Dấu hiệu thay sự vật (Attribute/Sign for Thing): a characteristic attribute stands for the person or thing that possesses it — e.g., áo trắng (white shirt) stands for "student" because white shirts are the Vietnamese school uniform.Cụ thể thay trừu tượng (Concrete for Abstract): a tangible physical thing stands for an abstract concept — e.g., mồ hôi (sweat) stands for "hard labor" or "effort."
Hoán dụ is widely used in Vietnamese journalism, political speech, everyday conversation, and song lyrics to achieve economy of expression. Because it relies on shared cultural knowledge, some hoán dụ constructions are specific to Vietnamese culture and may not translate directly into other languages.
How to Tell Them Apart in Practice
Apply this two-step diagnostic to any suspicious construction:
Step 1 — Similarity check: Could you insert "like" or "as" between the two elements and still make logical sense? If yes, you are in metaphor territory (ẩn dụ). Example: "Tuổi trẻ là mùa xuân" → youth is like spring (both fresh, energetic, new) → ẩn dụ.
Step 2 — Association check: Are the two elements literally connected in the real world — by physical proximity, causal relationship, part-to-whole structure, or cultural convention? If yes, you have hoán dụ. Example: "Áo trắng đến trường" → white shirts and students are connected because white shirts are literally what students wear → hoán dụ.
If neither similarity nor association is clear, the construction may simply be literal language, not a figure of speech at all.
Example Pairs
Pair 1 — Students
Ẩn dụ: Học sinh là những mầm non của đất nước.
Metaphor: Students are the young buds of the nation. (Students and buds share the quality of youth, fragility, and growth potential — a similarity-based comparison.)
Hoán dụ: Áo trắng đổ ra đường sau tiếng trống tan trường.
Metonymy: White shirts poured out onto the street after the school bell rang. (White shirt = student, because white shirts are the Vietnamese school uniform — a real-world attribute-for-person association.)
Pair 2 — Workers
Ẩn dụ: Công nhân là những bánh răng trong cỗ máy vĩ đại của xã hội.
Metaphor: Workers are the cogs in the great machine of society. (Workers and cogs share the quality of keeping a system running — a similarity-based comparison.)
Hoán dụ: Bàn tay đã xây dựng nên những công trình vĩ đại ấy.
Metonymy: Hands built those great structures. (Bàn tay = workers; the hand is the body part workers use — a part-for-whole association.)
Pair 3 — An experienced leader
Ẩn dụ: Người thầy là ngọn đuốc soi đường trong bóng tối.
Metaphor: The teacher is a torch lighting the way in the dark. (Teacher and torch share the quality of guiding others toward light — a similarity-based comparison.)
Hoán dụ: Mái đầu bạc ấy đã dẫn dắt công ty qua bao thăng trầm.
Metonymy: That gray head led the company through many ups and downs. (Gray hair = an elderly, experienced person; gray hair is the physical attribute conventionally associated with age and wisdom.)
Pair 4 — Reading an author's works
Ẩn dụ: Những trang thơ của Nguyễn Du là kho báu vô giá của văn học dân tộc.
Metaphor: The poems of Nguyễn Du are a priceless treasure of national literature. (Poetry is compared to treasure based on their shared quality of immense value.)
Hoán dụ: Tôi đang đọc Nguyễn Du để chuẩn bị cho kỳ thi văn học.
Metonymy: I am reading Nguyễn Du to prepare for the literature exam. (Nguyễn Du = his literary works; the author's name stands for the works he produced — an author-for-work association.)
Pair 5 — Love and emotion
Ẩn dụ: Tình yêu là ngọn lửa không bao giờ tắt trong lòng anh.
Metaphor: Love is a flame that never dies in his heart. (Love and flame share the qualities of intensity, warmth, and the capacity to consume — a similarity-based comparison.)
Hoán dụ: Trái tim ấy đã thuộc về người khác từ lâu rồi.
Metonymy: That heart has belonged to someone else for a long time. (Trái tim = a person's love and emotional life; the heart is the organ culturally associated with love and feeling.)
Pair 6 — A city or institution acting
Ẩn dụ: Hội An là viên ngọc trai lung linh giữa lòng miền Trung.
Metaphor: Hội An is a shimmering pearl in the heart of Central Vietnam. (Hội An and a pearl share the qualities of beauty, preciousness, and rarity.)
Hoán dụ: Hà Nội vừa ban hành quy định mới về quản lý đô thị.
Metonymy: Hanoi has just issued new regulations on urban management. (Hà Nội = the governmental authorities located in Hanoi — a place-for-institution association.)
Pair 7 — A sports player
Ẩn dụ: Anh ấy là con sư tử dũng mãnh trên sân cỏ.
Metaphor: He is a fierce lion on the football pitch. (Player and lion share the qualities of power, aggression, and dominance.)
Hoán dụ: Chiếc áo số 10 ghi bàn thắng quyết định ở phút bù giờ.
Metonymy: The number 10 jersey scored the decisive goal in added time. (The jersey number = the player wearing it; the number is a culturally recognized sign that identifies the player.)
Pair 8 — Youth and the passage of time
Ẩn dụ: Tuổi trẻ là mùa xuân tươi đẹp nhất của cuộc đời.
Metaphor: Youth is the most beautiful spring of one's life. (Youth and spring share qualities of freshness, energy, renewal, and brevity.)
Hoán dụ: Mồ hôi và nước mắt của cả đời ông đã tạo dựng nên cơ nghiệp này.
Metonymy: The sweat and tears of his whole life built this family fortune. (Mồ hôi = hard labor; nước mắt = suffering and sacrifice — concrete physical signs standing for abstract concepts.)
Common Patterns
Patterns Used for Ẩn dụ
Direct equation — X là Y (when X and Y are not literally the same but share a quality):
Kiến thức là ánh sáng dẫn đường cho nhân loại.
Knowledge is the light that guides humanity. (Knowledge and light share the quality of dispelling darkness and enabling progress.)
Synesthesia — crossing sensory domains (chuyển đổi cảm giác):
Màu sắc trong bức tranh ấy ồn ào và náo nhiệt lạ thường.
The colors in that painting are unusually loud and boisterous. (Sound vocabulary — ồn ào, náo nhiệt — applied to visual art; this is a synesthetic ẩn dụ.)
Giọng nói của cô ấy ngọt ngào như dòng suối mát.
Her voice is as sweet as a cool stream. (Taste — ngọt ngào — applied to sound; a synesthetic quality metaphor.)
Patterns Used for Hoán dụ
Part for whole (bộ phận thay toàn thể):
Nhiều cánh tay đã giơ lên ủng hộ đề xuất đó.
Many hands were raised in support of that proposal. (Cánh tay = people; the raised hand is the physical gesture that represents the person making it.)
Author for work (tác giả thay tác phẩm):
Trong giờ văn hôm nay, chúng tôi phân tích Hồ Xuân Hương.
In today's literature class, we analyzed Hồ Xuân Hương. (The poet's name stands for her body of poetry.)
Attribute for person (dấu hiệu thay sự vật):
Những tà áo dài duyên dáng tỏa sáng trong buổi lễ hội.
Graceful áo dài shone at the festival. (Áo dài = women wearing the traditional dress — the garment is the culturally iconic attribute that identifies the wearer.)
Place for institution (địa điểm thay tổ chức):
Nhà trắng chưa đưa ra bình luận nào về sự kiện này.
The White House has not yet commented on this event. (The building stands for the executive branch of government residing within it.)
Common Mistakes
Mistake 1 — Confusing Similarity with Association
The most widespread error is labeling a hoán dụ construction as ẩn dụ because the substitution seems poetic. The test is not whether the figure sounds literary, but whether the underlying link is similarity or association.
❌ "Áo trắng đến trường" là ẩn dụ vì học sinh giống như áo trắng về sự trong sáng.
✅ "Áo trắng đến trường" là hoán dụ vì áo trắng là đồng phục thực tế của học sinh — đây là mối liên hệ liên tưởng, không phải tương đồng về phẩm chất.
White shirts do not resemble students in any meaningful qualitative way; they are simply what students wear by school regulation. That real-world connection makes this hoán dụ. If the sentence were "Học sinh là những tờ giấy trắng tinh khiết" (Students are blank white pages), that would be ẩn dụ, because the comparison rests on a shared quality — purity and potential.
Mistake 2 — Assuming All "X là Y" Structures Are Ẩn Dụ
Students often assume that any predicate structure of the form "X là Y" automatically constitutes a metaphor. However, hoán dụ can appear in the same grammatical frame, and many "X là Y" sentences are entirely literal.
❌ "Ông Năm là tay vợt kỳ cựu" sử dụng ẩn dụ vì có cấu trúc "X là Y".
✅ "Ông Năm là tay vợt kỳ cựu" sử dụng hoán dụ: "tay vợt" dùng bộ phận (cánh tay cầm vợt) để chỉ toàn thể (vận động viên tennis) — đây là mối liên hệ thực tế, không phải tương đồng.
When you see "X là Y," identify the logic: does Y describe X through resemblance, or through a real-world instrument, part, or attribute? "Tay vợt" refers to a player because the hand holding the racket is literally how the sport is played — that is associative logic, which means hoán dụ regardless of the grammatical structure.
Mistake 3 — Labeling a Simile as an Ẩn Dụ
A simile (so sánh tu từ) uses explicit comparison words such as như, tựa như, or giống như, while a metaphor states the equation without those linking words. Confusing them is a common error on literature analysis tasks.
❌ "Mắt em sáng như sao" là một ẩn dụ vì so sánh mắt với sao.
✅ "Mắt em sáng như sao" là so sánh tu từ (simile). Ẩn dụ phải phát biểu trực tiếp: "Mắt em là hai vì sao sáng" — không dùng từ so sánh như "như" hay "tựa như".
The presence of như marks the construction as a simile. Remove như and state the equation directly — only then does it become ẩn dụ. This distinction carries full marks on NLTV C1–C2 literary analysis questions where candidates must name and classify the figure of speech precisely.
Mistake 4 — Inventing a Hoán Dụ With an Unclear Association
Metonymy only functions when the associative connection is culturally shared and immediately recognizable to the target audience. Creating a hoán dụ based on a private or obscure link produces confusion rather than meaning.
❌ Chiếc bút đỏ đã ký duyệt dự án ngay hôm qua.
✅ Giám đốc đã ký duyệt dự án ngay hôm qua.
Unless the surrounding text has firmly established that a red pen is the manager's personal iconic object, readers will not understand who or what "chiếc bút đỏ" refers to. Effective hoán dụ relies on shared cultural convention. Established cases like "áo trắng" for student or "tay vợt" for player work precisely because these associations are fixed in Vietnamese cultural knowledge.
Mistake 5 — Forcing an Unintuitive Ẩn Dụ
A metaphor functions only when the similarity between the two things is immediately apparent to readers. A forced or opaque metaphor reads as an error rather than a literary device, especially in formal academic or literary writing.
❌ Quyển sách ấy là một cái đinh vít trong cuộc đời tôi.
✅ Quyển sách ấy là người bạn đồng hành trung thành suốt những năm tháng khó khăn nhất của tôi.
Calling a book "a screw" establishes no recognizable similarity — there is no intuitive shared quality between a book and a fastening device. The corrected version uses "faithful companion," a metaphorical mapping that readers immediately understand because companionship and the role of a trusted book share clear qualities: constancy, support, and presence in difficult times.
Quick Quiz
Fill in the blank with ẩn dụ or hoán dụ:
Câu ca dao: "Thuyền về có nhớ bến chăng / Bến thì một dạ khăng khăng đợi thuyền" dùng hình ảnh thuyền và bến để nói về người đi xa và người ở lại. Đây là _____.
Hint: Are the boat and the riverbank similar in quality to the two people, or are they literally associated with those people in the real world?
Answer
Ẩn dụ. The boat (thuyền) represents the person who leaves, and the bank (bến) represents the one who stays and waits. There is no literal real-world connection between a specific boat and a specific person — the link is purely qualitative: the boat is mobile and departs while the bank is fixed and constant, just as one person travels while the other remains faithful. This is a quality-based metaphor (ẩn dụ phẩm chất) and a celebrated example from Vietnamese folk poetry. The emotional resonance comes precisely from mapping human loyalty onto the physical relationship between water and land.
Fill in the blank with ẩn dụ or hoán dụ:
Trong câu "Sài Gòn vừa công bố kế hoạch mở rộng tuyến metro," từ "Sài Gòn" được dùng để chỉ _____.
Hint: Does "Sài Gòn" in this sentence resemble the decision-maker in some quality, or is it literally the place where the decision-making body is located?
Answer
Hoán dụ. In this sentence, "Sài Gòn" does not describe the city's physical appearance or share a quality with the body making the announcement. It stands for the city government or the relevant municipal authority located in the city — a classic place-for-institution metonymy. The connection is spatial and institutional, not qualitative. Note that in a sentence like "Sài Gòn hôm nay trời mưa lớn" (It is raining heavily in Sài Gòn today), "Sài Gòn" is used literally as a location name with no figure of speech at all.
Fill in the blank with ẩn dụ or hoán dụ:
Trong thơ Tố Hữu: "Mặt trời của bắp thì nằm trên đồi / Mặt trời của mẹ, em nằm trên lưng" — hình ảnh "mặt trời" trong dòng thứ hai là _____.
Hint: Is the baby literally connected to the sun in the real world, or does the baby share certain qualities with the sun?
Answer
Ẩn dụ. The baby (em) is called "mặt trời" not because of any physical or institutional connection between a child and the actual sun, but because they share essential qualities: the sun brings warmth, light, and life to the world — and a beloved child brings exactly those same things to a mother's life. This is a quality-based metaphor (ẩn dụ phẩm chất) and one of the most celebrated examples of ẩn dụ in modern Vietnamese poetry. The first "mặt trời" in the couplet is literal (the real sun above the cornfield), making the contrast with the metaphorical second "mặt trời" all the more striking — a technique that demonstrates how ẩn dụ and literal language can coexist within a single poetic passage.