English uses can for two different jobs — I can swim is about me, can you pay by card here? is about the shop — and never marks the difference. Hebrew marks it with two different words, and picking the wrong one is one of the few learner errors Israelis actually notice, because it makes an ordinary question about a rule sound like a question about you personally.
The rule, and the test
יכול is a personal can. It attaches to a subject and agrees with them: אני יכול, היא יכולה, הם יכולים, הן יכולות.
אפשר is impersonal. It has no subject, it never inflects — no feminine, no plural, no first person, ever — and it means it is possible or one may.
So: is there a person doing the being-able? If yes, יכול. If you are asking whether a thing is possible or allowed at all, אפשר.
אפשר לשלם בכרטיס או רק במזומן?
efshár leshalém bekhartís o rak bimzumán?
Can we pay by card, or is it cash only? (asking about the shop)
אני לא יכולה לשלם בכרטיס, שכחתי אותו בבית.
aní lo yekholá leshalém bekhartís, shakhákhti otó babáyit
I can't pay by card, I left it at home. (f. speaker — about her, not about the shop)
Same eight words of content, two completely different questions. And notice what the impersonal buys you: אפשר puts the burden on nobody. Nobody is being asked to do anything, nobody is being told what they can and cannot manage — which is why it is the natural thing to say to a stranger behind a counter, and why so much of Hebrew's politeness runs through it. More of that machinery is on making a request politely.
אפשר לראות את החולצה בשחור?
efshár lir'ót et hakhultsá beshakhór?
Could I see that shirt in black?
אפשר עוד כוס מים, בבקשה?
efshár od kos máyim, bevakashá?
Could we have another glass of water, please? (אפשר takes a plain noun as happily as an infinitive)
Three things אפשר means
Milog gives it three senses, and they are worth separating because only two of them belong in speech.
| Sense | Milog's gloss | English |
|---|---|---|
| 1 — permission | מותר; אין מניעה לעשות דבר מה | you may, there's nothing stopping you |
| 2 — possibility | יש אפשרות; ניתן | it's possible to, you can |
| 3 — likelihood | ייתכן; יש סבירות ש־ | it may be that, possibly |
Senses 1 and 2 are the everyday ones and shade into each other constantly — can I park here is both a question about the rules and a question about the world. Sense 3 is a different construction: אפשר ש־ followed by a whole clause rather than an infinitive.
אפשר לחנות פה בשבת בלי תשלום.
efshár lakhanót po beshabát bli tashlúm
You can park here on Saturday without paying. (sense 1 — nothing stands in the way)
אפשר שהמסקנה הזאת מוקדמת מדי.
efshár shehamaskaná hazót mukdémet midáy
It may be that this conclusion is premature. (sense 3)
Past and future: one conjugates, one gets carried
יכול is a verb — an odd one, but a verb — so it has its own past and future: יכולתי, יכלה, and the future אוּכַל · תּוּכַל · יוּכַל · נוּכַל. The whole irregular paradigm is on יכול.
אפשר cannot be conjugated at all. It gets its tense from היה standing in front of it: היה אפשר for the past, יהיה אפשר for the future. Both are ordinary, frequent Hebrew — in Hebrew Wikipedia's article namespace, on 16 August 2026, היה אפשר came back between 1,114 and 1,146 across three runs and יהיה אפשר at 362 twice. (insource: figures on a common string drift between runs and are floors rather than exact counts, which is why the first is given as a band.)
| Present | Past | Future | |
|---|---|---|---|
| personal | אני יכול / יכולה | יכולתי | אוכל |
| impersonal | אפשר | היה אפשר | יהיה אפשר |
פעם היה אפשר להיכנס לשם בלי תור.
pá'am hayá efshár lehikanés leshám bli tor
You used to be able to get in there without queuing.
אחרי השיפוץ יהיה אפשר לשבת גם בחוץ.
akharéi hashipúts yihyé efshár lashévet gam bakhúts
After the renovation you'll be able to sit outside too.
Note that היה here does not agree with anything — there is nothing for it to agree with. It is always the bare masculine singular, whoever is speaking and however many of them there are.
The negatives are two different statements
This is where the choice stops being about politeness and starts changing what is true.
- לא יכול — this person is unable. Something about them.
- אי אפשר — it is not possible. Something about the world.
הוא לא יכול לבוא, הוא במילואים.
hu lo yakhól lavó, hu bemilu'ím
He can't come — he's on reserve duty. (about him)
אי אפשר לבוא בשבת, השער נעול.
i efshár lavó beshabát, hashá'ar na'úl
It's not possible to come on Saturday — the gate's locked. (about the situation; nobody's abilities are in question)
The negative particle is אי, not לא — a separate little word meaning non-, the same one in אי הבנה "misunderstanding" and אי שקט "restlessness". אי אפשר is two words and always has been.
Softening a request with אם אפשר
Milog lists אִם אֶפְשָׁר as a fixed expression and glosses it אם יורשה לי — "if I may". It is the ordinary way to take the edge off an instruction, and it goes at either end of the sentence.
אם אפשר, תשאירי לי את זה ליד הדלת.
im efshár, tash'íri li et ze leyád hadélet
If it's all right, leave it by the door for me. (to a woman)
אפשר בבקשה חשבון נפרד לכל אחד?
efshár bevakashá kheshbón nifrád lekhól ekhád?
Could we get separate bills, please? (observed usage — this is what you hear across a café counter; no dictionary consulted for this guide labels it for register)
Common Mistakes
1. Giving אפשר a subject. It is the single commonest error with this word, and it comes straight from English, where can needs somebody in front of it. אפשר has no subject slot and no feminine, plural or first-person form to inflect into.
❌ אני אפשר לעזור לך עם זה
Incorrect — אפשר takes no subject at all and never inflects. Either drop the pronoun (אפשר לעזור לך? 'can this be helped with?') or use the personal verb: אני יכול לעזור לך עם זה.
אני יכול לעזור לך עם זה, זה ייקח שתי דקות.
aní yakhól la'azór lekhá im ze, ze yikákh shtei dakót
I can help you with that, it'll take two minutes. (m. speaker, to a man)
2. Negating with לא instead of אי. The result is a perfectly good Hebrew sentence about somebody refusing permission.
❌ לא אפשר לשלם בכרטיס
he didn't allow payment by card
Incorrect as a reading — לא אפשר is the past of the verb אִפְשֵׁר, 'allowed, enabled'. The negative of the modal is two words: אי אפשר לשלם בכרטיס.
אי אפשר לשלם בכרטיס, המכשיר לא עובד מהבוקר.
i efshár leshalém bekhartís, hamakhshír lo ovéd mehabóker
You can't pay by card — the machine's been down since this morning.
3. Conjugating אפשר for the past. English could is a verb form, so learners build one — and again the form they build already exists as something else.
❌ אפשרתי לבוא מוקדם יותר
I let someone come earlier
Incorrect as a reading — אפשרתי is the pi'el verb, 'I allowed / I enabled'. The impersonal past is היה אפשר, and if you mean yourself it is the personal verb: יכולתי לבוא מוקדם יותר.
יכולתי לבוא מוקדם יותר, פשוט לא ידעתי שהתחילו בשבע.
yakhólti lavó mukdám yotér, pashút lo yadáti shehitkhílu beshéva
I could have come earlier — I just didn't know they started at seven.
4. Asking about a rule with יכול. Not an error of grammar, and both sentences below are ✅ — but they ask different things, and English speakers reach for the first when they mean the second.
אתה יכול לצלם פה?
atá yakhól letsalém po?
Can you take photos here? (to a man — about him: is he in a position to, is he allowed to)
אפשר לצלם פה, או שאסור?
efshár letsalém po, o she'asúr?
Is photography allowed here, or not? (about the place — the question you actually wanted)
Key Takeaways
- יכול belongs to a person and agrees — יכול, יכולה, יכולים, יכולות. אפשר belongs to nobody and never inflects, in any tense, for any speaker.
- The test: is there a person doing the being-able? If not, אפשר. Asking about a shop, a rule or a place is an אפשר question.
- The impersonal puts the burden on nobody, which is why so many Israeli requests run through it: אפשר את החשבון, אפשר עוד כוס מים.
- Milog gives אפשר three senses — permitted, possible, and it may be that. The third takes a clause (אפשר ש־) and, on the evidence of where it turns up, is something to read rather than to say; speech uses יכול להיות ש־.
- Tense: יכול conjugates (יכולתי, אוכל); אפשר is carried by היה and יהיה, which never agree with anything.
- The negatives say different things. לא יכול = this person is unable. אי אפשר = it is not possible — and the particle is אי, two words, never לא.
- Watch the two forms that already exist as something else: לא אפשר is "he didn't allow" and אפשרתי is "I enabled".
Now practice Hebrew
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Start learning Hebrew →Related Topics
- אפשר and אי אפשר: Possible and ImpossibleA2 — Use invariant אפשר with an infinitive for possibility and polite requests, negate it with אי אפשר, and distinguish it from the verb אִפְשֵׁר.
- יכול: Can, May, MightA2 — Use the agreeing verb יכול for ability, permission, and possibility, and choose its irregular past and future forms accurately.
- Impersonal Predicates: כיף, נעים, חבל, קשה, כדאיB1 — Build Hebrew experiencer sentences with a default masculine-singular predicate and a ל־marked person, while recognizing where the same words agree outside this frame.
- מותר and אסור: Permitted and ForbiddenA2 — Use frozen מותר and אסור with a ל־ participant and an infinitive for permission and prohibition, while allowing normal agreement outside the modal frame.
- Making a Request PolitelyA2 — Build natural Hebrew requests with אפשר, אולי, בבקשה, רוצה and future forms such as תוכל—without mistaking directness for a lack of politeness.
- יכול: The Verb With No Real FutureB1 — Four cells of one paradigm, built four different ways: a present that inflects like an adjective, a past on the rare פָּעֹל pattern, a future on a u-stem that looks like it came from another binyan, and an infinitive that exists only on paper.