काश (kaash)

interjection An interjection/particle expressing a wish for something that is unreal, unlikely, or contrary to fact -- roughly English 'if only' or 'I wish'. It has essentially one core use, always paired with the subjunctive or a counterfactual construction.
Sense 1 : expresses a wistful or counterfactual wish
interjection Typically opens the sentence and is followed by a subjunctive or past-counterfactual verb form, often closed with कि (ki) introducing the wished-for clause, e.g. काश कि... (kaash ki).
Synonyms: अगर (agar, only in older/regional counterfactual use), ऐसा होता कि (aisaa hotaa ki, descriptive paraphrase, not a true synonym)
Frequency: high
Cultural Note: काश (kaash) carries a sigh built into it -- you'll hear it in Bollywood dialogues and everyday complaints alike, as in काश मैं वहाँ होता (kaash main vahaan hotaa, 'if only I had been there'). It comes from Persian and still has that slightly poetic, heartfelt ache to it, making it a favorite in ghazals and film lyrics as well as ordinary rueful conversation.
Common Mistakes: 1) Learners often follow काश (kaash) with a simple present or future verb; native speakers use it almost only with the subjunctive or the 'would have' past-counterfactual construction (होता (hotaa), आता (aataa), etc.), never with the plain habitual or definite future. 2) काश (kaash) is not used for ordinary polite requests or simple hopes about the future (for that, use चाहिए (chaahie) or की उम्मीद है (kii ummiid hai)) -- it specifically signals regret or longing for something that did not/does not/will not easily happen.
Sample Sentences:
काश मैं वहाँ होता। If only I had been there.
(kaash main vahaan hotaa।)
Register: Neutral -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
काश तुम मुझे पहले बता देते। I wish you had told me earlier.
(kaash tum mujhe pahle bataa dete।)
Register: Casual -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
काश मेरे पास इतना पैसा होता। If only I had that much money.
(kaash mere paas itnaa paisaa hotaa।)
Register: Casual -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
काश वह अब भी जिंदा होता। If only he were still alive.
(kaash vah ab bhii jindaa hotaa।)
Register: Literary -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
काश हम फिर से बच्चे बन सकते। If only we could become children again.
(kaash ham phir se bachche ban sakte।)
Register: Literary -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
काश यह पल कभी खत्म न होता। If only this moment would never end.
(kaash yah pal kabhii khatm n hotaa।)
Register: Literary -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
काश मैंने वह नौकरी न छोड़ी होती। If only I hadn't quit that job.
(kaash mainne vah naukrii n chhodii hotii।)
Register: Neutral -- Mood: Counterfactual -- Aspect: Perfective -- Voice: Active
काश तुम्हें मेरा दर्द समझ आता। I wish you understood my pain.
(kaash tumhen meraa dard samajh aataa।)
Register: Literary -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
अरे काश, मैं भी तुम्हारे साथ चल पाता! Ah, if only I could have come along with you too!
(are kaash, main bhii tumhaare saath chal paataa!)
Register: Casual -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
काश ज़िंदगी इतनी आसान होती जितनी लगती है। If only life were as easy as it seems.
(kaash zindgii itnii aasaan hotii jitnii lagtii hai।)
Register: Literary -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active
काश आप उस दिन मेरी बात मान लेते। If only you had listened to me that day.
(kaash aap us din merii baat maan lete।)
Register: Formal -- Mood: Counterfactual -- Aspect: Habitual -- Voice: Active