Kell or muszáj: how do you say must, have to and need in Hungarian?

Use kell by default: Mennem kell is "I have to go", and Kell egy toll? is "Do you need a pen?". Muszáj means the same "have to", but it is more informal and stronger, closer to "I really have no choice": Muszáj mennem. The two also behave differently in grammar, because kell is a verb and muszáj is not, and neither of them gives you "must not".

The rule: same meaning, different strength and grammar

Dictionaries treat the two as synonyms. Wiktionary glosses both as "must, have to" and lists each as a synonym of the other. So any sentence with muszáj + infinitive can be rephrased with kell and stay correct. The reverse is not true, and that is what learners need to know.

• Kell is the neutral, all-purpose word. It works in speech, writing, rules, recipes and official texts. It has two senses: "must, need to" with an infinitive, and "to be needed" with a noun as its subject (Kell nekem az a ház, "I need that house").
• Muszáj adds pressure. Better Hungarian calls it stronger than kell, a word that "emphasizes an urgency", and more informal. The elon.io course describes it as "quite strong: it implies that you don't really have a choice", less formal than szükséges ("necessary") but not slang. It has only the "have to" sense.

Their origins differ too: Wiktionary traces kell to a Proto-Finno-Ugric root meaning "to be necessary", while muszáj is borrowed from German muss sein, "must be".

Nine ways to talk about obligation, in one table

English "must", "have to", "need", "should" and "mustn't" spread across more Hungarian words than learners expect. The columns are the questions that decide which one you can use.

Two patterns stand out. Only the kell family can take a thing you need as its subject. And the words that are not verbs (muszáj, kénytelen, köteles, szabad, tilos) all form their past with volt and their future with lesz.

Who has to: the infinitive carries the person

Kell and muszáj share one construction. Neither can show the person on itself, so the person goes on the infinitive as a possessive-style ending (mennem, menned, mennie), and can also be named in the dative. Better Hungarian notes that muszáj takes exactly the same infinitive endings as kell.

• Mennem kell. I have to go.
• Muszáj mennem. I really have to go.
• Annának holnap dolgoznia kell. Anna has to work tomorrow.

Without an ending, the infinitive makes a general statement: Itt cipőt kell viselni, "Shoes must be worn here". The full table of endings (látnom, látnod, látnia...) is on the infinitive page.

Notice the word order in the first two examples. In a neutral sentence the infinitive comes before kell (Mennem kell), while muszáj normally comes first (Muszáj mennem). Better Hungarian gives the same contrast.

What happens to a verbal prefix

This is the grammatical difference you will hear most often. Kell behaves like the auxiliaries fog, akar, tud: in a neutral sentence the prefix of the infinitive jumps in front of it. Muszáj does not pull the prefix away, as Better Hungarian notes, so the infinitive stays whole.

Under negation the prefix stays on the infinitive with both words; the general rule is on the verbal prefixes page.

Past, future and "should": where the two really differ

Kell is a verb and conjugates. Muszáj is not. Wiktionary classes it as a noun used only as a predicate, and explains that it "cannot have any inflection characteristic of a verb"; it forms its tenses with van, like an adjective. László Elekfi, describing the Hungarian inflectional dictionary in Magyar Nyelvőr, puts it in one line: as a predicate, muszáj is ragozhatatlan, uninflectable.

The -ett of kellett is the regular past tense. Do not copy it onto muszáj: there is no *muszájt or *muszájott.

Kellene and kéne: "should"

"Should" and "ought to" are the conditional of kell: kellene, which Wiktionary lists with the colloquial short form kéne. Hunlang's grammar notes give the past as kellett volna, "should have".

• Nem kéne felhívnod a szüleidet? Shouldn't you call your parents?
• Nem kellett volna új bankszámlát nyitnod. You shouldn't have opened a new bank account.

Needing a thing: kell or szükség, never muszáj

When English "need" has a noun as its object, Hungarian turns the sentence round: the thing needed is the subject of kell, and the person who needs it goes in the dative. Wiktionary groups kell with tetszik, ízlik and hiányzik: verbs whose subject is the thing and whose experiencer is in the dative, as on the szeret or tetszik page.

• Kell egy toll? Do you need a pen?
• Nem kell, köszönöm. No thanks, I don't need it.
• Kellenek a jegyek? Do you need the tickets?
• Kellesz nekem. I need you.

Because the thing is the subject, the verb agrees with it: plural kellenek for the tickets, second person kellesz when "you" are what is needed. Both forms are in Wiktionary's conjugation table. It is also why "me too" after Kell egy kávé is Nekem is, not Én is: see én is or nekem is.

Muszáj has no "be needed" sense, so *Muszáj egy toll does not work. The other option is the noun szükség, "need": the thing goes in -ra/-re and the person is shown by a possessive ending, szükségem van, "I have need".

• Pénzre van szüksége. He needs money.
• Több türelemre van szükség. More patience is needed.

Must not: nem kell, nem szabad or tilos

English "must not" and "don't have to" look alike and mean opposite things. Hungarian uses different words.

• Nem kell = there is no need. Nem kell jönnöd, "You don't have to come". Nem muszáj says the same, more casually: "you don't have to, but you can".
• Nem szabad = it is not allowed. Wiktionary lists nem szabad and tilos as the opposites of szabad, "allowed". Nem szabad elfelejtened, "You mustn't forget".
• Tilos = forbidden. The word of signs and regulations: Belépni tilos ("No entry"), Dohányozni tilos ("No smoking").

Why does the other answer circulate? Because nem kell is often used as a gentle "don't": Better Hungarian notes it can say something "should not be done or is pointless". Nem kell kiabálni! is literally "There's no need to shout", and in context it works as "Stop shouting". That is a polite hint, not a prohibition. If you mean that something is not allowed, nem szabad is the word. Where nem sits in these sentences is covered on the nem, ne and sem page.

Kénytelen and köteles: forced, or obliged by a rule

Two adjectives take a personal subject, like English "I am forced" and "I am obliged".

• Kénytelen means "forced, compelled": circumstances leave you no choice. Wiktionary's example is Kénytelen leszek elmenni oda, "I will have to go there".
• Köteles means "obliged" by a rule, contract or law. Wiktionary's examples: A felhasználó köteles ezt a mezőt kitölteni ("The user must enter data in this field") and Nem vagy köteles beszélni velük ("You don't have to talk to them").

So the strength scale runs from rules (köteles) through neutral need (kell) to personal pressure (muszáj, kénytelen), with kellene as the soft "should" below them all.

Ha muszáj, ha kell: the short answers

Both words can stand alone when the verb is obvious. elon.io glosses Ha muszáj as "if we really have to, if it can't be avoided", and notes that muszáj in the "if" clause with kell in the main clause is very common:

• Ha muszáj, a főnöknek is szólni kell. If we really have to, the boss has to be told too.
• Kell? Nem muszáj. Is it necessary? You don't have to.

Common learner errors

• *Muszájt mennem or *Muszájott mennem for "I had to go". Muszáj never changes form: Muszáj volt mennem, or Mennem kellett.
• *Muszáj egy toll for "I need a pen". Only kell takes a noun: Kell egy toll, or Szükségem van egy tollra.
• *Én kell mennem. The person is never in the nominative with kell: Mennem kell, or Nekem mennem kell for emphasis.
• Nem kell dohányozni for "Smoking is not allowed". That says "there's no need to smoke": use Nem szabad dohányozni or Dohányozni tilos.
• *Kell elmennem as a neutral sentence. The prefix moves in front: El kell mennem.

Where the rule stops

• Strength is a tendency, not a rule. The descriptions of muszáj as stronger come from learner guides; dictionaries list the two as plain synonyms. Swapping muszáj for kell + infinitive is always grammatical; it only lowers the pressure.
• "Must" as a guess. English "he must be tired" is a conclusion, not an obligation. Neither kell nor muszáj covers it: Wiktionary's translations for that sense are biztos, biztosan, bizonyára: Biztosan fáradt.

Sources and further reading

• Wiktionary, "kell" and "muszáj" (Hungarian): senses, etymology, conjugation, the usage note on muszáj volt and muszáj lesz, and the note on dative experiencer verbs
• Wiktionary, "kellene", "kéne", "kénytelen", "köteles", "szükség", "szabad" and "tilos"; English "must" and "have to" (Hungarian translations)
• László Elekfi, "A magyar szókincs szófaji arányai a Magyar ragozási szótár tükrében", Magyar Nyelvőr 123/2 (muszáj as an uninflectable predicate)
• Better Hungarian, "Have to/Must/Need: Kell / Muszáj / Szükség"; Hunlang, "Modal verbs: kellene"
• elon.io, "Ha muszáj, a főnöknek is szólni kell" and "muszáj"

Frequently asked questions