क़सम खाना (qasam khaanaa)

verb A compound expression meaning 'to swear/take an oath'; क़सम (qasam) is the borrowed noun for 'oath' and खाना (khaanaa) here does not mean 'to eat' but functions as a light verb completing the idiom.
Sense 1 : to swear an oath, to vow
verb, transitive Takes की (kii) to mark what is sworn on: क़सम खाना (kisii kii qasam khaanaa) 'to swear on someone/something'. The person swearing is the subject and takes ने (ne) in the perfective, following ordinary transitive agreement.
Synonyms: प्रतिज्ञा करना (pratigyaa karnaa, formal), सौगंध खाना (saugandh khaanaa, variant form)
Frequency: high
Cultural Note: Swearing on a loved one is everyday emotional currency in Hindi-speaking households -- माँ की क़सम (maan kii qasam, 'I swear on my mother') or तेरी क़सम (terii qasam, 'I swear on you') are heard constantly in arguments, promises, and playful insistence, often more as an emphatic rhetorical flourish than a literal binding oath. It pairs naturally with the noun क़सम (qasam) alone, which can stand as an interjection-like assurance on its own without the verb.
Common Mistakes: 1) Learners sometimes try to translate literally and use खाना (khaanaa) with its 'eating' sense in mind, but here it is a fixed pairing with क़सम (qasam) and carries no food meaning at all. 2) The thing sworn on is marked with की (kii) (तुम्हारी क़सम खाता हूँ, tumhaarii qasam khaataa hoon, 'I swear on you'), not से (se) or पर (par), which learners sometimes guess instead.
Sample Sentences:
मैं तुझे सच बताने की क़सम खाता हूँ। I swear that I'll tell you the truth.
(main tujhe sach bataane kii qasam khaataa hoon।)
Register: Casual -- Mood: Indicative -- Aspect: Habitual -- Tense: Present -- Voice: Active
उसने माँ की क़सम खाई कि वह फिर कभी झूठ नहीं बोलेगा। He swore on his mother that he would never lie again.
(usne maan kii qasam khaaii ki vah phir kabhii jhooth nahiin bolegaa।)
Register: Casual -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Active
तेरी क़सम, मैंने तेरा फोन नहीं छुआ। I swear on you, I didn't touch your phone.
(terii qasam, mainne teraa phon nahiin chhuaa।)
Register: Casual -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Active
गवाह ने अदालत में सच बोलने की क़सम खाई। The witness swore an oath to speak the truth in court.
(gavaah ne adaalat men sach bolne kii qasam khaaii।)
Register: Formal -- Mood: Indicative -- Aspect: Perfective -- Tense: Past -- Voice: Active
क़सम खा कि तू मुझसे कुछ नहीं छिपाएगी। Swear that you won't hide anything from me.
(qasam khaa ki too mujhse kuchh nahiin chhipaaegii।)
Register: Casual -- Mood: Imperative -- Voice: Active
अगर मैं क़सम खाता, तो तुम्हें यकीन हो जाता? If I swore an oath, would you believe me?
(agar main qasam khaataa, to tumhen yakiin ho jaataa?)
Register: Casual -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
नए मंत्री पद और गोपनीयता की क़सम खा रहे हैं। The new ministers are taking the oath of office and secrecy.
(nae mantrii pad aur gopniiytaa kii qasam khaa rahe hain।)
Register: Formal -- Mood: Indicative -- Aspect: Continuous -- Tense: Present -- Voice: Active
शायद वह डर के मारे झूठी क़सम खा ले। Maybe he'll swear a false oath out of fear.
(shaayad vah dar ke maare jhoothii qasam khaa le।)
Register: Neutral -- Mood: Subjunctive -- Voice: Active
बच्चों की क़सम, अब मैं सिगरेट नहीं छुऊँगा। I swear on my children, I won't touch a cigarette again.
(bachchon kii qasam, ab main sigret nahiin chhuoongaa।)
Register: Casual -- Mood: Indicative -- Tense: Future -- Voice: Active
प्राचीन काल में योद्धा अपने राजा के प्रति निष्ठा की क़सम खाते थे। In ancient times, warriors would swear an oath of loyalty to their king.
(praachiin kaal men yoddhaa apne raajaa ke prati nishthaa kii qasam khaate the।)
Register: Literary -- Mood: Indicative -- Aspect: Habitual -- Tense: Past -- Voice: Active
जब तक क़सम न खाई जाए, कोई उसकी बात पर भरोसा नहीं करेगा। Unless an oath is sworn, no one will trust what he says.
(jab tak qasam n khaaii jaae, koii uskii baat par bharosaa nahiin karegaa।)
Register: Formal -- Mood: Subjunctive -- Voice: Passive
Morphology
Verb
infinitive: क़सम खाना (qasam khaanaa)
infinitive oblique: क़सम खाने (qasam khaane)
habitual/simple (sg.m): क़सम खाता (qasam khaataa)
habitual/simple (pl.m): क़सम खाते (qasam khaate)
habitual/simple (sg.f): क़सम खाती (qasam khaatii)
habitual/simple (pl.f): क़सम खातीं (qasam khaatiin)
continuous (sg.m): क़सम खा रहा (qasam khaa rahaa)
continuous (pl.m): क़सम खा रहे (qasam khaa rahe)
continuous (sg.f): क़सम खा रही (qasam khaa rahii)
continuous (pl.f): क़सम खा रहीं (qasam khaa rahiin)
perfective (sg.m): क़सम खाया (qasam khaayaa)
perfective (pl.m): क़सम खाए (qasam khaae)
perfective (sg.f): क़सम खाई (qasam khaaii)
perfective (pl.f): क़सम खाईं (qasam khaaiin)
imperative (informal): क़सम खा (qasam khaa)
imperative (neutral): क़सम खाओ (qasam khaao)
imperative (formal): क़सम खाइए (qasam khaaie)
future (1sg.m): क़सम खाऊँगा (qasam khaaoongaa)
future (1sg.f): क़सम खाऊँगी (qasam khaaoongii)
future (1pl.m): क़सम खाएँगे (qasam khaaenge)
future (1pl.f): क़सम खाएँगी (qasam khaaengii)
future (2sg.m): क़सम खाएगा (qasam khaaegaa)
future (2sg.f): क़सम खाएगी (qasam khaaegii)
future (2pl.m): क़सम खाओगे (qasam khaaoge)
future (2pl.f): क़सम खाओगी (qasam khaaogii)
future (3sg.m): क़सम खाएगा (qasam khaaegaa)
future (3sg.f): क़सम खाएगी (qasam khaaegii)
future (3pl.m): क़सम खाएँगे (qasam khaaenge)
future (3pl.f): क़सम खाएँगी (qasam khaaengii)
subjunctive (1sg): क़सम खाऊँ (qasam khaaoon)
subjunctive (1pl): क़सम खाएँ (qasam khaaen)
subjunctive (2sg): क़सम खाए (qasam khaae)
subjunctive (2pl): क़सम खाओ (qasam khaao)
subjunctive (3sg): क़सम खाए (qasam khaae)
subjunctive (3pl): क़सम खाएँ (qasam khaaen)