क्यों (kyon)

adverb/particle/interjection The everyday interrogative for 'why'; also has a common tag-question use meaning 'right?' / 'isn't it?' at the end of a sentence, and appears in a few fixed rhetorical phrases.
Sense 1 : why (asking for a reason)
adverb
Synonyms: किस लिए (kis lie, for what reason), काहे (kaahe, colloquial)
Frequency: high
Cultural Note: This is the basic 'why' every learner needs early -- a small child in Delhi asking क्यों? क्यों? (kyon? kyon?, 'why? why?') on repeat is a familiar sound to any parent here.
Common Mistakes: 1) Learners often put क्यों (kyon) at the very end of the sentence as in English word-for-word thinking; in a genuine question it belongs near the front, right before or near the verb phrase, e.g. तुम क्यों नहीं आए? (tum kyon nahiin aae?, 'why didn't you come?'). 2) क्यों (kyon) asks for a reason, while किसलिए (kislie) leans toward purpose ('for what') -- the two overlap heavily in casual speech, but learners sometimes reach for क्यों (kyon) where a native speaker would naturally say किसलिए (kislie) and vice versa without real harm.
Sample Sentences:
तुम आज स्कूल क्यों नहीं गए? Why didn't you go to school today?
(tum aaj skool kyon nahiin gae?)
Register: Casual -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Active
वह हर रोज़ देर से क्यों आता है? Why does he come late every day?
(vah har roz der se kyon aataa hai?)
Register: Neutral -- Mood: Indicative -- Aspect: Habitual -- Tense: Present -- Voice: Active
बच्चा बार-बार पूछ रहा था, "क्यों? क्यों?" The child kept asking again and again, "why? why?"
(bachchaa baar-baar poochh rahaa thaa, "kyon? kyon?")
Register: Casual -- Mood: Indicative -- Aspect: Continuous -- Tense: Past -- Voice: Active
आप इतने परेशान क्यों हैं? Why are you so worried?
(aap itne pareshaan kyon hain?)
Register: Formal -- Mood: Indicative -- Aspect: Perfective -- Tense: Present -- Voice: Active
मुझे नहीं पता कि वह क्यों रो रही थी। I don't know why she was crying.
(mujhe nahiin pataa ki vah kyon ro rahii thii।)
Register: Neutral -- Mood: Indicative -- Aspect: Continuous -- Tense: Past -- Voice: Active
अगर वह सच बोल रहा था, तो पुलिस को क्यों बुलाया गया? If he was telling the truth, then why was the police called?
(agar vah sach bol rahaa thaa, to pulis ko kyon bulaayaa gayaa?)
Register: Neutral -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Passive
अगर तुम्हें पता होता, तो तुम मुझे बताते ही क्यों नहीं? If you had known, then why wouldn't you have just told me?
(agar tumhen pataa hotaa, to tum mujhe bataate hii kyon nahiin?)
Register: Casual -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
क्यों न हम कल मिलें और बात करें? Why don't we meet tomorrow and talk?
(kyon n ham kal milen aur baat karen?)
Register: Neutral -- Mood: Subjunctive -- Voice: Active
यह मशीन काम क्यों नहीं करेगी, यह कोई नहीं जानता। Nobody knows why this machine won't work.
(yah mashiin kaam kyon nahiin karegii, yah koii nahiin jaantaa।)
Register: Neutral -- Mood: Indicative -- Tense: Future -- Voice: Active
यह फैसला आखिर क्यों लिया गया, इसकी जांच होनी चाहिए। There should be an inquiry into why this decision was taken at all.
(yah phaislaa aakhir kyon liyaa gayaa, iskii jaanch honii chaahie।)
Register: Formal -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Passive
मुझे बताओ कि तुमने ऐसा क्यों किया। Tell me why you did that.
(mujhe bataao ki tumne aisaa kyon kiyaa।)
Register: Casual -- Mood: Imperative -- Voice: Active
Sense 2 : tag question marker (right?, isn't it?)
particle Placed at the end of a statement to turn it into a confirmation-seeking tag question, often with rising intonation: तुम आ रहे हो, क्यों? (tum aa rahe ho, kyon?, 'you're coming, aren't you?').
Synonyms: ना (naa, softer tag), है ना (hai naa, phrase variant)
Frequency: medium
Cultural Note: You'll hear this a lot in banter and gentle challenges -- someone teasing a friend might say तुमने ही किया, क्यों? (tumne hii kiyaa, kyon?, 'you did it, didn't you?') with a knowing smile, using क्यों (kyon) almost like a verbal nudge rather than a real question.
Common Mistakes: 1) This tag-question क्यों (kyon) is not literally asking 'why' -- a learner who translates it word-for-word will misread the sentence's intent; it functions more like English 'right?' tacked onto a statement.
Sample Sentences:
तुमने ही किया, क्यों? You did it, didn't you?
(tumne hii kiyaa, kyon?)
Register: Casual -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Active
तुम मुझसे नाराज़ हो, क्यों? You're angry with me, aren't you?
(tum mujhse naaraaz ho, kyon?)
Register: Casual -- Mood: Indicative -- Tense: Present -- Voice: Active
तुम्हें भी यह गाना पसंद है, क्यों? You like this song too, don't you?
(tumhen bhii yah gaanaa pasand hai, kyon?)
Register: Casual -- Mood: Indicative -- Tense: Present -- Voice: Active
वह कल नहीं आएगा, क्यों? He won't come tomorrow, will he?
(vah kal nahiin aaegaa, kyon?)
Register: Casual -- Mood: Indicative -- Tense: Future -- Voice: Active
तुम रोज़ यहाँ आते हो, क्यों? You come here every day, right?
(tum roz yahaan aate ho, kyon?)
Register: Casual -- Mood: Indicative -- Aspect: Habitual -- Tense: Present -- Voice: Active
आप उससे मिल चुके हैं, क्यों? You've already met him, haven't you?
(aap usse mil chuke hain, kyon?)
Register: Neutral -- Mood: Indicative -- Tense: Present -- Voice: Active
यह किताब तुमने ही रखी थी, क्यों? You're the one who put this book here, weren't you?
(yah kitaab tumne hii rakhii thii, kyon?)
Register: Neutral -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Active
अगर तुम सच बताते, तो सब ठीक हो जाता, क्यों? If you had told the truth, everything would have been fine, wouldn't it have?
(agar tum sach bataate, to sab thiik ho jaataa, kyon?)
Register: Casual -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
आप इस मामले में मेरी मदद करेंगे, क्यों? You'll help me with this matter, won't you?
(aap is maamle men merii madad karenge, kyon?)
Register: Formal -- Mood: Indicative -- Tense: Future -- Voice: Active
यह फैसला जल्दी में लिया गया था, क्यों? This decision was made in a hurry, wasn't it?
(yah phaislaa jaldii men liyaa gayaa thaa, kyon?)
Register: Neutral -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Passive
Sense 3 : rhetorical/challenging 'why' (as a standalone retort)
interjection Used alone or nearly alone as a sharp retort or rhetorical challenge, often implying defiance or disbelief rather than genuinely requesting information.
Synonyms: क्यों नहीं (kyon nahiin, why not, related phrase)
Frequency: medium
Cultural Note: Said with a certain edge -- क्यों? (kyon?) thrown back at someone who's just given an order can carry real attitude, the verbal equivalent of raising an eyebrow; the classic retort क्यों नहीं? (kyon nahiin?, 'why not?!') has that same defiant energy.
Sample Sentences:
क्यों? Why should I?!
(kyon?)
Register: Casual -- Mood: Indicative -- Voice: Active
अभी जाओ! -- क्यों? Go now! -- Why should I?!
(abhii jaao! -- kyon?)
Register: Casual -- Mood: Imperative -- Voice: Active
मुझे माफी माँगनी चाहिए? क्यों भला? I should apologize? Why on earth should I?!
(mujhe maaphii maangnii chaahie? kyon bhalaa?)
Register: Casual -- Mood: Subjunctive -- Tense: Present -- Voice: Active
क्यों नहीं? Why not?!
(kyon nahiin?)
Register: Casual -- Mood: Indicative -- Voice: Active
तुम यह काम नहीं कर सकते! -- क्यों नहीं? You can't do this work! -- Why not?!
(tum yah kaam nahiin kar sakte! -- kyon nahiin?)
Register: Casual -- Mood: Indicative -- Tense: Present -- Voice: Active
मैं वहाँ नहीं जाऊँगा। क्यों जाऊँ? I'm not going there. Why should I go?!
(main vahaan nahiin jaaoongaa। kyon jaaoon?)
Register: Casual -- Mood: Subjunctive -- Tense: Future -- Voice: Active
तुझे इतनी जल्दी क्यों? Why are you in such a hurry, huh?!
(tujhe itnii jaldii kyon?)
Register: Casual -- Mood: Indicative -- Tense: Present -- Voice: Active
उसने कहा माफी माँग लो, तो मैंने कहा क्यों? He said apologize, so I said why should I?!
(usne kahaa maaphii maang lo, to mainne kahaa kyon?)
Register: Casual -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Active
और क्यों नहीं भई, बिल्कुल करूँगा! And why not indeed, of course I'll do it!
(aur kyon nahiin bhaii, bilkul karoongaa!)
Register: Casual -- Mood: Indicative -- Tense: Future -- Voice: Active
मुझसे यह सवाल क्यों? Why is this question directed at me, huh?!
(mujhse yah savaal kyon?)
Register: Casual -- Mood: Indicative -- Tense: Present -- Voice: Active