唔知 + Question Word

When you want to express uncertainty or report that you don't know a specific piece of information, you use 唔知 (m4 zi1) followed by the question clause. Note that 唔知 is a common contraction of the more formal full form 唔知道 (m4 zi1 dou6, often pronounced with a changed tone as dou3 in colloquial speech).

Key features of this pattern:

• Word Order: The word order remains identical to a direct question. For example, 'Who is he?' is 佢係邊個？ (keoi5 hai6 bin1 go3?). 'I don't know who he is' is 我唔知佢係邊個 (ngo5 m4 zi1 keoi5 hai6 bin1 go3).
• Subject Dropping: It is highly natural in Cantonese to omit the subject pronoun. Instead of explicitly saying 我唔知 (ngo5 m4 zi1), you can start a sentence directly with 唔知 (m4 zi1).
• 唔知 vs. 唔識: Remember that 唔知 (m4 zi1) is used for facts and information. If you want to say you don't know a person (as an acquaintance), a language, or how to do a skill, you use 唔識 (m4 sik1). However, if you are talking about knowing someone's identity (a fact), you still use 唔知 (e.g., 我唔知佢係邊個 - ngo5 m4 zi1 keoi5 hai6 bin1 go3, 'I don't know who he is').
• Particle Rules: In direct questions, we often use the particle 呀 (aa3). In an indirect question statement, this inner particle is usually dropped. However, the particle 呢 (ne1) is frequently kept or added to the end of the indirect question to soften the statement or express wondering. If the entire sentence is a question (e.g., 'Do you know...?'), you can use a sentence-final particle for the main clause, though it is optional if the main clause uses a V-not-V structure.
• The 'If/Whether' Shortcut: To say 'I don't know if...', you can use the V-not-V structure, or the universal shortcut 係咪 (hai6 mai6) before the verb.
• Alternative Questions: To say 'I don't know if A or B', use 定係 (ding6 hai6) between the choices.
• The Dilemma Pattern: A very common structure is 唔知 + verb/question word combination + 好 (hou2). This expresses a dilemma, meaning 'I don't know what is best to do.' The verb's position depends on the question word. For adverbs like 點 (dim2), the verb comes after (e.g., 唔知點算好 - m4 zi1 dim2 syun3 hou2, 'I don't know what to do'). For objects or locations, the verb comes before the question word (e.g., 唔知食咩好 - m4 zi1 sik6 me1 hou2, 'I don't know what to eat').
• Aspect Markers: Aspect markers like 咗 (zo2) remain attached to the verb inside the question clause, not to 唔知. For example, 我唔知佢買咗咩 (ngo5 m4 zi1 keoi5 maai5 zo2 me1) is correct, not 我唔知咗佢買咩.
• The 'For Some Reason' Phrase: The set phrase 唔知點解 (m4 zi1 dim2 gaai2) literally means 'I don't know why', but it frequently functions as a standalone adverbial phrase meaning 'for some unknown reason' (e.g., 唔知點解佢好嬲 - m4 zi1 dim2 gaai2 keoi5 hou2 nau1, 'For some reason, he is very angry').
• Expressing Wonder: Adding the particle 呢 (ne1) to the end of an '唔知' sentence is the standard Cantonese equivalent of the English phrase 'I wonder...'. This is the direct translation learners should use when they want to express wondering or thinking out loud.
• The 'So/Very' Idiom: A very common idiomatic use is 唔知幾 (m4 zi1 gei2) + Adjective. Despite containing 'not know', this actually means 'so' or 'very'. For example, 唔知幾好 (m4 zi1 gei2 hou2) means 'so good'.
• The '都' Emphasizer: To express total cluelessness or exasperation, you can add 都 (dou1) before 唔知. For example, 我都唔知佢講乜！ (ngo5 dou1 m4 zi1 keoi5 gong2 mat1! - 'I have absolutely no idea what he is saying!').