對於

1. Grammatical Function
對於 (deoi3 jyu1) is a preposition (or coverb) that introduces the object of an attitude. It highlights the target of a specific emotion, policy, or viewpoint. Unlike general topic markers, it explicitly prepares the listener for a statement of stance.

2. Sentence Structure & Positioning
It can appear in several main positions:

• Sentence-initial: [對於 + Topic], [Subject] + [Predicate].
  Example: 對於呢件事，我冇補充。(Regarding this matter, I have no further comment.) Note: Both 對於 and 對 (deoi3) can be used at the absolute beginning of a sentence, though 對於 sounds more formal.
• Post-subject: [Subject] + [對於 + Topic] + [Predicate].
  Example: 政府對於環境保護好重視。(The government attaches great importance to environmental protection.) Crucially, when placed between the subject and the verb in spoken Cantonese, the simpler 對 is vastly preferred. Using 對於 in this position often sounds clunky and bookish (e.g., '我對佢冇感覺' is natural; '我對於佢冇感覺' is unnatural).
• Attributive: [對於 + Topic + 嘅 + Noun].
  Example: 社會對於呢件事嘅睇法 (Society's viewpoint regarding this matter)

3. Register and Usage
對於 is a formal word. It is frequently used in news broadcasts, legal documents, and formal speeches. In everyday casual conversation, using 對於 on its own sounds slightly bookish, and speakers overwhelmingly prefer the simpler 對 (deoi3).

4. Common Pattern: 對於...嚟講
A common set phrase is 對於...嚟講 (deoi3 jyu1... lei4 gong2), which means 'As far as... is concerned' or 'For...'.
Example: 對於我嚟講，呢個決定好難。(For me / As far as I am concerned, this decision is very difficult.) Note that the slightly shorter 對...嚟講 (deoi3... lei4 gong2) is also highly frequent and often preferred in casual speech.

5. Common Collocations
Because 對於 introduces the target of an attitude or reaction, it frequently pairs with specific nouns. Common collocations include:

• 睇法 (tai2 faat3) - viewpoint
• 態度 (taai3 dou6) - attitude
• 影響 (jing2 hoeng2) - influence / impact
• 感覺 (gam2 gok3) - feeling
• 評價 (ping4 gaa3) - evaluation

6. Critical Restrictions
Unlike the general preposition 對 (deoi3), 對於 has specific restrictions:

• Interpersonal Treatment: It cannot be used for direct interpersonal treatment. It can refer to people if they are the topic of an attitude (e.g., 'Regarding this candidate...'), but not for how someone treats someone else. Correct: 佢對我好好 (He is very good to me). Incorrect: 佢對於我好好。
• Direction of Action/Speech: It cannot be used to indicate the recipient or direction of a physical action or speech. You must use 對 for this. Correct: 佢對我笑 (He smiled at me) or 佢對我講 (He spoke to me). Incorrect: 佢對於我笑 / 佢對於我講。
• Abstract vs. Physical: 對於 is strictly for abstract attitudes, whereas 對 can also mean physically 'facing' something (e.g., 對住個海 - facing the sea) or 'matching' (e.g., 對答案 - checking answers).

7. Distinction from 關於
Learners often confuse 對於 with 關於 (gwaan1 jyu1).

• 對於 means 'towards' and marks the target of an attitude (e.g., 'My feelings towards the city').
• 關於 means 'about' or 'concerning' and marks the scope or contents of a subject matter (e.g., 'A book about the city').
• Standalone Titles: 關於 can be used as a standalone title or heading (e.g., 關於香港歷史 - About Hong Kong History), whereas 對於 cannot stand alone as a title.