Key Facts
- Hangul: 다이어트하다 (daieoteuhada)
- Meaning: to diet
- Level: A2
- Syllables: 6 (다 · 이 · 어 · 트 · 하 · 다)
- Stem: 다이어트하
- Conjugation class: 하다 type
- Object marking: intransitive
- Polite present: 다이어트해요
What Does 다이어트하다 Mean?
다이어트하다 is usually used on its own, with no object: 다이어트해요 is a complete sentence. If you keep the noun and the verb apart, say 다이어트를 해요. To say you are on a diet right now, 다이어트 중이에요 is the common phrase.
The word is colloquial and very common in everyday talk.
How Do You Pronounce 다이어트하다?
Daieoteuhada has 6 syllables (다 · 이 · 어 · 트 · 하 · 다) and is said as it is spelled.
How Do You Use 다이어트하다 in a Sentence?
저는 여름 전에 다이어트해요.
I diet before summer.
다이어트해요 is the polite present form.
친구는 작년에 다이어트해서 십 킬로 뺐어요.
My friend dieted last year and lost ten kilos.
다이어트해서 is the because / and then form.
다이어트하면 먼저 식습관을 바꾸세요.
If you diet, change your eating habits first.
다이어트하면 is the if (conditional) form.
Usage Notes
The three examples show a diet that is seasonal, remembered and advised. 저는 여름 전에 다이어트해요 sets a time, the past story says a friend lost ten kilos, and 다이어트하면 먼저 식습관을 바꾸세요 gives advice with the honorific 세요 ending. Exercise is a separate idea: 운동하다 is for moving your body, and 다이어트하다 is about weight.
How Does Daieoteuhada Conjugation Work?
다이어트하다 (to diet) follows the 하다 pattern: the 하 of the stem 다이어트하 meets 여 and contracts to 해, which gives 다이어트해요 and 다이어트했어요. The short negative of 다이어트하다 (to diet) is 다이어트 안 해요, with 안 placed after the noun part; see negating 하다 verbs.
The pattern behind 다이어트하다 (to diet) is taught step by step in 하다 to 해요.
다이어트하다
| Form | Korean | Romanization | Rule |
|---|---|---|---|
| Polite present | 다이어트해요 | ||
| Polite past | 다이어트했어요 | ||
| Polite future (plan) | 다이어트할 거예요 | ||
| Polite future (intention or guess) | 다이어트하겠어요 | ||
| Formal present | 다이어트합니다 | ||
| Formal past | 다이어트했습니다 | ||
| Formal future | 다이어트할 것입니다 | ||
| Casual present | 다이어트해 | ||
| Casual past | 다이어트했어 | ||
| Casual future | 다이어트할 거야 | ||
| Want to (polite) | 다이어트하고 싶어요 | ||
| Honorific polite | 다이어트하세요 | ||
| Because / and then | 다이어트해서 | ||
| If (conditional) | 다이어트하면 | ||
| Present modifier (before a noun) | 다이어트하는 | ||
| Past modifier (before a noun) | 다이어트한 | ||
| Future modifier (before a noun) | 다이어트할 | ||
| Negative with 안 (short) | 다이어트 안 해요 | ||
| Negative (long form) | 다이어트하지 않아요 |
Before a noun, 다이어트하다 (to diet) becomes 다이어트하는 (present) or 다이어트한 (past); as a link between clauses it is 다이어트해서 for 'because' and 다이어트하면 for 'if'.
Sound Changes
| Form | Korean | Sounds like |
|---|---|---|
| Polite past | 다이어트했어요 | [다이어트해써요] |
| Future (plan) | 다이어트할 거예요 | [다이어트할꺼예요] |
| Future (guess) | 다이어트하겠어요 | [다이어트하게써요] |
| Formal present | 다이어트합니다 | [다이어트함니다] |
| Formal past | 다이어트했습니다 | [다이어트핻씀니다] |
| Formal future | 다이어트할 것입니다 | [다이어트할꺼심니다] |
| Casual past | 다이어트했어 | [다이어트해써] |
| Casual future | 다이어트할 거야 | [다이어트할꺼야] |
| Want to | 다이어트하고 싶어요 | [다이어트하고 시퍼요] |
| Long negative | 다이어트하지 않아요 | [다이어트하지 아나요] |
Common Mistake
Wrong: ✗ 다이어트를 해해요
Correct: ✓ 다이어트해요 / 다이어트를 해요
Why: Learners double the 하다: either attach 하다 directly (다이어트해요) or use 다이어트를 해요, not both.
다이어트하다 Versus Similar Words
| Word | How it differs |
|---|---|
| 운동하다 | 운동하다 is to exercise; 다이어트하다 is to lose weight, which may or may not include exercise. |
Declining Cake at a Café
Two friends are ordering at a café. One asks about sharing cake, and the other explains a current choice without telling the friend what to order.
Jisu
케이크도 먹을까요?
Keikeudo meogeulkkayo?
Shall we have cake too?
Alex
저는 요즘 다이어트해요.
Jeoneun yojeum daieoteuhaeyo.
I’m dieting these days.
Jisu
저도 작년에 다이어트했어요.
Jeodo jangnyeone daieoteuhaesseoyo.
I dieted last year too.
Alex
그럼 오늘은 커피만 마셔요.
Geureom oneureun keopiman masyeoyo.
Then let’s just have coffee today.
요즘 gives 다이어트해요 an ongoing time frame: “these days.” 작년에 places 다이어트했어요 in the previous year. The verb reports the speaker’s activity rather than a result. The last line proposes what the friends will order on this occasion; the conversation does not say that coffee itself causes weight loss.
What Does the Korean Loanword 다이어트 Mean?
English “diet” can mean everything a person usually eats. Korean 다이어트 most often means an effort to lose or manage weight. For a meal plan or the composition of meals, 식단 is a useful word; for eating habits, use 식습관. Those nouns name different parts of the situation rather than repeating 다이어트.
다이어트하다 describes an activity or effort. It does not state that weight was lost. The existing example about losing ten kilos adds a separate result with 뺐어요. Without that extra result, 다이어트했어요 only tells you that the person dieted. English “lost weight” would add information the verb itself does not supply.
Likewise, 운동하다 describes exercising. A person may exercise for sport, enjoyment, or fitness without calling it 다이어트. When explaining a routine, choose the verb that names the purpose or activity you actually mean rather than using both as automatic translations of one another.
Phrases You May See on Packaging and in Conversation
다이어트 중이에요 means “I’m on a diet.” 중 points to something in progress. It is useful when explaining a current food choice without listing a routine. The noun phrase 다이어트 중 can also appear in a short caption or personal status message.
다이어트 식단 means a meal plan intended for dieting, and 다이어트 식품 means food marketed for dieting. The wording tells you the intended use or marketing category. It does not tell you the ingredients, portion size, or what effect eating it will have. Those are separate facts from the meaning of the label.
체중 관리 means weight management. You may see this broader noun phrase in fitness information. 체중 is body weight, while 관리 means management or care. The expression can discuss maintaining weight as well as changing it, so it is not always a direct replacement for “losing weight.”
What Is Tricky about Conjugation and Spacing?
The full verb is written 다이어트하다, and the attached polite form is 다이어트해요. If you choose the noun construction, write 다이어트를 해요. The particle 를 belongs to the noun, and 해요 already contains the conjugated 하다. Adding another 해 would repeat the verb instead of making the sentence more complete.
In 다이어트 안 해요, the short negative sits between the noun part and 해요. In 다이어트하지 않아요, the long negative follows the intact verb stem. Both describe not dieting. Neither says that the speaker does not eat, avoids all food, or has stopped exercising.
다이어트하세요 can be an instruction or suggestion directed at someone else. Even with a polite ending, an unsolicited comment about another person's weight can feel intrusive. The first-person forms in the dialogue explain the speaker's own choice. They are useful for ordering without judging what a companion eats.
| Related word | Meaning | How it differs |
|---|---|---|
| 식단 | meal plan / menu | Names the planned foods or meals. |
| 식습관 | eating habits | Describes recurring habits rather than one meal. |
| 체중 | body weight | Names what is measured. |
| 운동 | exercise | An activity that may have purposes besides weight loss. |
The gym and fitness vocabulary lesson teaches the exercise words that often appear near 다이어트 in everyday talk.
Mini Drill: Build the Right Form
- Give the polite past of 다이어트하다.
- Rewrite 다이어트하다 as a noun plus 하다, keeping 를.
- Write the short negative in polite speech.
- Give the “want to” form without repeating 하다.
Show drill answers
- 다이어트했어요. It reports dieting in the past.
- 다이어트를 하다; in polite speech, 다이어트를 해요.
- 다이어트 안 해요. Leave spaces around 안.
- 다이어트하고 싶어요. There is only one 하다 stem.
Quick Self-Test
- Does 다이어트했어요 prove that someone lost weight?
- Which noun means eating habits?
- Does 다이어트 식품 on a label guarantee a particular result?
Show answers
- No. It describes the activity; a result needs additional wording.
- 식습관. 식단 instead names the meal plan.
- No. The phrase identifies the intended use or marketing category.
Frequently Asked Questions
How Do You Say 'I Diet before Summer' in Korean?
저는 여름 전에 다이어트해요. The verb needs no object; 여름 전에 sets the time.
How Is 다이어트하다 (to diet) Different from 운동하다?
운동하다 is to exercise; 다이어트하다 is trying to lose weight, which may or may not include exercise.
Is 다이어트를 해해요 Correct Korean?
No. Use 다이어트해요 or 다이어트를 해요: attach 하다 directly or make 다이어트 the object of 하다, but do not double it.
How Do I Say I Am on a Diet?
다이어트 중이에요 is the usual phrase for a diet that is still going on.
What Is the Polite past of 다이어트하다?
For 'to diet', the polite past is 다이어트했어요; the polite present is 다이어트해요.
How Do You Say 'Not Diet' with 다이어트하다?
For 'not diet', the short negative is 다이어트 안 해요 and the long one is 다이어트하지 않아요.
Which Words Are Related to 다이어트하다?
- 운동하다 (to exercise)
- 건강하다 (healthy)
- 날씬하다 (slim)
- 뚱뚱하다 (fat)
- Korean verb dictionary
What Should You Learn Next?
Try other forms of 다이어트하다 in the Korean verb conjugator, then continue with 운동하다 (to exercise). More entries like 다이어트하다 (to diet) sit together in the Korean verb dictionary.