אינני, אינך, אינו: Inflected אין

Everyday Hebrew treats אין as one unchanging word. Formal written Hebrew does not: there it inflects for person, agreeing with its subject the way a verb would, and it stands in front of a participle or a nominal predicate as a kind of negative copula. This page is that paradigm. Treat it as a reading and formal-writing skill — you will meet these forms constantly in print and produce them only when you are writing something meant to sound official. The everyday sentence is on negating a verbless sentence.

The paradigm

Ten slots. The vowel differences are the whole difficulty, so the table is pointed.

Exactly three of the ten slots carry a second form, and the reason is historical rather than semantic. The Academy of the Hebrew Language's answer on איני ואינני settles it: אינני, איננו and איננה come from Biblical Hebrew — Isaiah 1:15 has גַּם כִּי תַרְבּוּ תְפִלָּה אֵינֶנִּי שֹׁמֵעַ, and Ecclesiastes 1:7 וְהַיָּם אֵינֶנּוּ מָלֵא — while איני, אינו and אינה come from the Hebrew of the rabbis. There is no difference in meaning, and both members of each pair are usable in every context. The other seven slots have one form each and nothing to choose.

Two ambiguities the textbooks never print

אינך is one spelling for two words. Unpointed, אֵינְךָ einkhá (to a man) and אֵינֵךְ einékh (to a woman) are the identical three letters. Nothing in the writing separates them, so a reader has to take the gender from elsewhere in the sentence — which, in a formal text addressed to an unnamed reader, is often nowhere.

איננו is genuinely two words, even pointed. The first-person plural form and the Biblical third-person masculine singular are both אֵינֶנּוּ, vowel for vowel — Jeremiah 44:16 uses it for we, אֵינֶנּוּ שֹׁמְעִים אֵלֶיךָ, we are not listening to you. So הוא איננו means he is not and אנחנו איננו means we are not, and the form itself will not tell you which. Genesis 37:30 is the famous instance of the singular: Reuben finds the pit empty and says הַיֶּלֶד אֵינֶנּוּ — the boy is gone — where nothing but the subject standing in front of it fixes the reading.

What it can and cannot attach to

The inflected form negates a predicate, never a finite verb. It takes a participle, a noun or an adjective — and a past or future verb is closed to it absolutely. There is no formal register in which אינני ידעתי is possible; the past and the future are negated with לא and with nothing else.

The choice in the first row — whether a present-tense participle takes לא or אינו — is a register decision with a long history behind it, and it is settled on negating the participle.

Where you will actually meet it

Legal boilerplate, product disclaimers, signage, academic prose, newspaper editorials and literary narration. That is the whole list, and it is worth memorising, because it is also the list of places where you may write it.

Read those two together and the split is obvious. The first is not a more polite version of the second; it is a different kind of text, and the person who says the first one aloud in a car park has misjudged something.

The classical construction, for recognition

Older and literary Hebrew also puts bare אין in front of an explicit subject, with the predicate after it: אין הוא מבין, אין הדבר כן. Modern prose has largely replaced this with the inflected form, but it survives in translations of classical texts, in rabbinic writing and in deliberately elevated style.

Outside the paradigm altogether sits a poetic form worth recognising once: Psalms 73:5 has אֵינֵמוֹ, with the archaic plural suffix ־מוֹ where prose would have אֵינָם.

Common Mistakes

1. Treating אינני as an invariable word. It is the form that gets taught first — usually in a sentence like אינני יודע — and a learner who files it under not rather than under I am not then attaches it to every subject in sight.

2. Putting a past-tense verb after it. English I did not know has one negator for every tense, so the Hebrew form that translates I am not gets pressed into service for I was not and I did not.

3. Saying it out loud. This is not a grammatical error and nobody will correct it, which is exactly why it persists. Using אינני in conversation is the precise mirror image of using האם to ask a question at a bus stop: both are correct, both are printed, and both announce that the speaker learned Hebrew from written material. Both sentences below are right; only the second one is speech.

4. Adding a second negator. The inflected form has already negated the clause, so nothing else in it negates — no לא beside it, and no לא inside it. That is the same negative-concord system that makes אין לי כלום work, and it is set out on אין.

Key Takeaways

• Ten slots, agreeing with the subject in person, gender and number. It behaves like a negative copula, not like an adverb.
• Three slots carry two forms: אינני/איני, אינו/איננו, אינה/איננה. Biblical against Mishnaic, no difference in meaning, both usable everywhere.
• Unpointed אינך is two words — אֵינְךָ einkhá and אֵינֵךְ einékh — and print does not separate them.
• אֵינֶנּוּ is two words even pointed: we are not, and the Biblical he is not of הַיֶּלֶד אֵינֶנּוּ. Only the subject decides.
• איננו can state plain absence at the end of a clause, where אינו cannot: אבא איננו.
• It attaches to a participle, a noun or an adjective. A past or future verb takes לא, in every register.
• The register list is short and closed: legal text, disclaimers, signage, academic prose, editorials, literary narration. Elsewhere, say לא.
• Classical אין plus an explicit subject — אין הוא מבין, אין הדבר כן — is recognition only.