知

Know That

Level 2Sounds Like zi1

知 (zi1) is the colloquial way to say "to know" when referring to facts, information, or situations. It is often followed by a full clause (e.g., "I know [he is coming]") and frequently ends with the particle 嘅 (ge3) to emphasize the assertion of a fact.

How It Works

1. Factual vs. Personal Knowledge
The most important rule is that 知 (zi1) is for information. If you want to say you know a person, a language, or how to do something, you must use 識 (sik1) instead. For example, you 知 (know) someone's phone number, but you 識 (know/are acquainted with) the person themselves.

2. The Role of 嘅 (ge3)
Sentences using 知 often end with the particle 嘅 (ge3). In this context, 嘅 acts as an assertive marker. It frames the information as a confirmed fact or a known state of affairs.
Example: 我知佢唔嚟嘅 (ngo5 zi1 keoi5 m4 lai4 ge3) — "I know (the fact) that he isn't coming."

3. Negation and Questions
To say "don't know," use 唔知 (m4 zi1). To ask "do you know?", the most natural way is the A-not-A question form: 知唔知 (zi1 m4 zi1). While you might hear 知唔知道, it is much less common in casual speech.

4. Register
知 is highly informal. In formal writing or very polite speech, you will see the full version 知道 (zi1 dou6). However, in almost all spoken contexts in Hong Kong, the single syllable 知 is preferred when followed by a clause.

Examples (5)

  1. 我知佢住邊。

    I know where he lives.

    Word by Word: I know he live where.

    Here, 知 is used because the object is a piece of information (his location).

  2. 你知唔知佢去咗邊呀？

    Do you know where he went?

    Word by Word: You know not know he go [perfective] where [particle]?

    This uses the 知唔知 question pattern to ask about a fact.

  3. 我唔知佢係邊個。

    I don't know who he is.

    Word by Word: I not know he is who.

    Even though 'who' refers to a person, 知 is used because you are talking about the identity (a fact), not personal acquaintance.

  4. 我知佢唔食辣嘢嘅。

    I know (the fact) that he doesn't eat spicy food.

    Word by Word: I know he not eat spicy thing [assertion].

    The 嘅 at the end emphasizes that this is an established fact the speaker is aware of.

  5. 佢知唔知聽日放假呀？

    Does he know that tomorrow is a holiday?

    Word by Word: He know not know tomorrow release holiday [particle]?

    A standard way to ask if someone is aware of a specific situation.

Common Mistakes

  • Using 識 (sik1) to express knowledge of a fact.

    我識佢去咗邊。
    我知佢去咗邊。

    Learners often confuse 知 (factual knowledge) with 識 (sik1) (acquaintance/skill). Since 'where he went' is a fact, you must use 知.

  • Using 知 (zi1) when you mean 'know a person'.

    Different Meaning我知你個朋友。
    我識你個朋友。

    To say you are acquainted with or recognize a person, you must use 識 (sik1). Using 知 here sounds like you only know of their existence as a piece of data.

  • Using the longer 知唔知道 when 知唔知 is the shorter form.

    Different Meaning你知唔知道？
    你知唔知？

    你知唔知道？ is correct and common. 知唔知 is the shorter form that many speakers use in quick questions.

How It Connects

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

知Level 2Know That

Learn This First

To use '知' (to know), you need to be comfortable with basic sentence structure and pronouns. It is also helpful to understand the assertion particle '嘅', which often closes the clause that follows '知'.

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