צריך, חייב or מוכרח?

Three words cover the ground English gives to need, have to and must. The usual advice is to rank them by strength — and the strength ranking, as far as it goes, is that צריך is everyday need, חייב is obligation, and מוכרח is compulsion. What this page adds is the parts of that picture you can actually check, because the sources do not print a clean scale, and there are three places where the words come apart hard enough to change what a sentence means. Permission and prohibition — מותר and אסור — are on their own page, the four agreeing forms of צריך on צריך, and the wider negation patterns on negating a modal.

Start with what the dictionary does not give you

Milog has no register field — where it labels at all it does so inside the gloss, as with ברם — and it defines these three in a circle. צריך's third sense is glossed חייב; מוכרח. חייב's first sense is glossed אין לו ברירה, מוכרח; צריך. Each is defined by the other two, which is a fair description of how much of their territory is shared — and a warning against announcing a tidy scale the dictionary declines to print. Where all three take an infinitive and the situation is an ordinary obligation, they overlap, and a native speaker choosing between them is choosing emphasis.

There is one asymmetry the dictionary does print, and it is worth having. Only חייב carries obligations with a source. Its second sense is אשם — at fault, liable, as in a court finding — and its third is a person who has to return what they borrowed, i.e. a debtor. Neither of the other two words does any of that.

מוכרח is a passive participle, and it shows

This one is not an adjective that happens to mean must. Milog files מוּכְרָח as the present tense of the huf'al verb הֻכְרַח, on the root כ־ר־ח, and glosses it נאלץ לפעול בניגוד לרצונו; אולץ — made to act against his own will. Every example sentence in that entry uses the past: הוא הוכרח לעזוב את ביתו בעקבות המלחמה. The literal content of מוכרח, in other words, is not I must but I have been made to, and it sits in a paradigm with the active הִכְרִיחַ "forced someone to". That is where its sense of having no room to move comes from.

Being a participle, it inflects like one: מוכרח · מוכרחה · מוכרחים · מוכרחות. The feminine you will meet is מוכרחה — in the same Wikipedia sample, מוכרחה outnumbers the strictly regular מוכרחת by 123 to 31.

Be honest about that second sentence: nobody has compelled the speaker to do anything. Everyday מוכרח has stretched past its etymology into plain emphasis, and you will read תנועתנו מוכרחה לקבוע רק עקרון אחד and אני מוכרחה לשיר in contexts with no compeller in sight. The morphology explains the flavour; it does not license translating every מוכרח as was forced. It is also by far the rarest of the three: in the past frame, Hebrew Wikipedia's article namespace returns הייתי צריך 248, הייתי חייב 80, הייתי מוכרח 11 (insource:/…/, 16 August 2026, each figure run twice with the same result).

Where they genuinely come apart: what follows them

An infinitive is the shared ground. A plain noun is not, and this is the difference that changes meanings rather than shades them.

Milog's first sense for צריך is simply זקוק ל־, need — and that sense is the one חייב does not have at all. Put a noun after חייב and you are in the world of debts.

Where they come apart hardest: the negative

This is the section to memorise. None of the three negates to must not. English collapses two different operations onto one shape — you don't have to and you must not — and Hebrew keeps them in separate words.

None of them has a past or a future of its own

They are not verbs, so they cannot be conjugated for tense. All three build their past with היה, which agrees along with them, and Hebrew mostly builds the future the same way — except for צריך, which has a genuine future verb of its own, הצטרך.

Common Mistakes

1. Reaching for חייב because the English said have to. English has no everyday word for plain need with an infinitive, so have to does that work — and mapping it onto חייב makes ordinary errands sound like court orders. Both sentences below are correct Hebrew; only one of them is what you meant about the bank.

2. Reading לא חייב as must not. The commonest and the costliest of the four, because the Hebrew is perfectly good and says the opposite of what you meant.

3. Conjugating them like verbs. English I had to is a past-tense verb form, so learners build one. There is no past of חייב — but there is a real, unrelated verb that looks exactly like the form you would invent.

4. Using מוכרח as a stronger צריך for ordinary things. It works, and it is not an error — but it is doing real emphatic work, and spending it on a haircut is like saying I am compelled to. Both are ✅; the difference is how much weight you have put on the sentence.

Key Takeaways

• Milog defines all three in a circle — צריך by חייב; מוכרח, חייב by מוכרח; צריך — and prints no register label on any of them. Where all three take an infinitive, they overlap, and the choice is emphasis.
• Only חייב carries obligations with a source: it also means liable, at fault and, as a noun, debtor.
• מוכרח is the huf'al present of הֻכְרַח, "was made to act against his will", and inflects as a participle (מוכרחה, not מוכרחת, by 123 to 31 in one written corpus). Everyday use has stretched it into plain emphasis — do not translate every מוכרח as was forced. It is the rarest of the three: 248 / 80 / 11 in the הייתי frame.
• The complement splits them. צריך + noun = need it; חייב + noun = owe it; מוכרח wants an infinitive.
• None of them negates to must not. לא צריך cancels the need, לא חייב cancels the obligation — and prohibition is אסור, a different word.
• No past, no future of their own. היה carries all three (הייתי חייב), and only צריך has a real future verb, אצטרך.