ai đó / gì đó

Someone or Other

Level 4

Adding đó (or đấy in the North) directly after a question word turns it into an indefinite pronoun. For example, ai (who) becomes ai đó (someone).

How It Works

How to form it:
Place đó (standard/Southern preference) or đấy (primarily Northern) immediately after question words. Note that đấy can be used with all of these question words just like đó. Because Vietnamese is an isolating language, the words remain separate and uninflected. These compounds are flexible and can act as either the subject or the object of a sentence:

  • ai đó / ai đấy = someone. You can also add một to heavily emphasize "a certain someone" (e.g., một ai đó).
  • gì đó / gì đấy / cái gì đó = something
  • đâu đó / đâu đấy / ở đâu đó = somewhere. Colloquially, đâu đó is also used as an adverb meaning "approximately" or "around" when talking about numbers, prices, or timeframes (e.g., Giá đâu đó khoảng 500 ngàn).
  • khi nào đó / khi nào đấy / lúc nào đó = sometime
  • sao đó / sao đấy = for some reason / somehow. In spoken Vietnamese, it is also frequently used as a predicate adjective meaning "weird", "off", or "unusual". Native speakers frequently reduplicate the question word for emphasis: sao sao đó (e.g., Người tôi cứ sao sao đó).
  • thế nào đó / thế nào đấy = somehow / in a certain way (standard/formal)
  • (một) [Noun] + nào đó = some [noun] / a certain [noun] (e.g., một người nào đó, một ngày nào đó). Note that unlike the standalone pronouns above, nào acts as an adjective modifying a noun. In casual speech, native speakers frequently use [Noun] + gì đó as an alternative (e.g., chuyện gì đó).

Important Distinctions:
1. Does not mean anyone in negative sentences, yes/no questions, or if-clauses: To say "I don't see anyone", use a bare question word: Tôi không thấy ai. If you say Tôi không thấy ai đó, it is grammatically valid but means "There is a certain someone I do not see" (the unknown variable takes scope above the negation). Similarly, use bare question words in yes/no questions (Có ai ở nhà không?) and if-clauses (Nếu ai hỏi...).
2. Not "anyone at all": Ai đó means a specific unknown person ("someone"). If you mean "no matter who" ("anyone"), use bất cứ ai.
3. Natural phrasing: While Có ai đó... (Someone is...) is grammatically correct, native speakers often prefer Có người... (There is a person...) for natural flow.
4. Literal questions vs. Indefinite pronouns: These exact same word combinations are frequently used as literal questions (e.g., Ai đó? = "Who is that?", Cái gì đó? = "What is that?"). Context, intonation, and punctuation distinguish the indefinite pronoun from the literal question.

Note: đó is not a special suffix; it is simply the demonstrative pronoun ("that/there") repurposed to point to an unknown variable.

Examples (5)

  1. Có ai đó đang gõ cửa.

    Someone is knocking on the door.

    Word by Word: Have who that currently knock door.

    Here, 'ai đó' acts as the subject of the action, referring to a specific but unknown person.

  2. Tôi muốn ăn cái gì đó.

    I want to eat something.

    Word by Word: I want eat thing what that.

    'Cái gì đó' or simply 'gì đó' is used when you want a thing, but haven't specified exactly what it is.

  3. Chắc anh ấy đã đi đâu đó rồi.

    He must have gone somewhere already.

    Word by Word: Sure brother that already go where that already.

    'Đâu đó' refers to an unspecified location.

  4. Hình như tôi đã gặp cô ấy ở đâu đấy.

    It seems I have met her somewhere.

    Word by Word: Shape like I already meet aunt that at where that.

    In Northern Vietnamese, 'đấy' is frequently used instead of 'đó' with the exact same meaning.

  5. Chúng ta sẽ gặp lại nhau vào một lúc nào đó.

    We will meet again sometime.

    Word by Word: We will meet again together on one moment which that.

    'Lúc nào đó' or 'khi nào đó' refers to an unspecified time in the future.

Common Mistakes

  • Using 'ai đó' or 'gì đó' in negative sentences to mean 'anyone' or 'anything'.

    Different MeaningTôi không thấy ai đó.
    Tôi không thấy ai cả.

    English speakers often translate 'I don't see anyone' word-for-word. In Vietnamese, bare question words like 'ai' act as 'anyone' in negative sentences. While 'Tôi không thấy ai đó' is grammatically valid, it actually means 'There is a certain someone I do not see' (the unknown variable takes scope above the negation), rather than 'I don't see anyone'.

  • Overusing 'ai đó' when a native speaker would use 'người' (person).

    Có ai đó tìm anh.
    Có người tìm anh.

    While 'có ai đó' is grammatically correct for 'someone', native speakers often prefer the existential 'có người' (there is a person) for natural, everyday speech.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

ai đó / gì đóLevel 4Someone or Other

Learn This First

To understand 'ai đó' and 'gì đó', you first need to know the basic question words for 'who' and 'what'. You also need to be familiar with the demonstrative 'đó' (that), which in this specific construction functions as a marker of indefiniteness rather than a pointer to a specific object.

Words in This Pattern

ai đóai