Saying how sure you are is one of the most frequent things you do in any language — "definitely", "probably", "maybe", "I doubt it". German offers three overlapping systems to do this: sentence adverbs (wahrscheinlich, vielleicht), modal verbs used epistemically (muss, dürfte, könnte, mag), and the Futur I for present assumptions (wird wohl … sein). English leans heavily on the modal-verb system (must, might, may); German speakers move fluidly between all three, and the modal-verb route in particular is where learners systematically under-perform. This page maps the whole scale and shows the German-specific moves that competitors gloss over.
The certainty scale at a glance
| Level | Adverbs | Modal / Futur | English feel |
|---|---|---|---|
| Certain | bestimmt, sicher(lich), ganz bestimmt, auf jeden Fall, zweifellos, definitiv | muss (strong inference) | definitely, surely, for sure |
| Probable | wahrscheinlich, höchstwahrscheinlich, vermutlich, wohl, anscheinend / offenbar | dürfte; wird (wohl) | probably, presumably, evidently |
| Possible | vielleicht, eventuell, möglicherweise, unter Umständen, kann sein | kann / könnte; mag | maybe, possibly, could be |
| Doubtful / negative | wohl kaum, kaum, eher nicht | ich bezweifle, dass …; ich glaube nicht, dass … | hardly, I doubt that |
| Excluded | auf keinen Fall, keinesfalls, unmöglich | kann nicht (sein) | no way, impossible |
High certainty: bestimmt, sicher, auf jeden Fall
At the top of the scale sit the confidence adverbs. bestimmt and sicher(lich) both mean "certainly / surely" and are the everyday workhorses; ganz bestimmt and zweifellos ("without doubt") ramp it up; definitiv is a slightly more modern, emphatic "definitely". auf jeden Fall ("in any case / definitely") doubles as a commitment ("I'll definitely come"). One subtlety English speakers miss: a high-certainty adverb often signals a confident prediction rather than a known fact — Sie kommt bestimmt means "she'll surely come", i.e. the speaker is betting on it, not reporting it. See sentence adverbs.
Der Zug hat bestimmt Verspätung, bei dem Wetter.
The train's surely delayed, in this weather.
Ich komme auf jeden Fall zu deiner Feier, das ist sicher.
I'm definitely coming to your party, that's for sure.
Probable: wahrscheinlich, vermutlich, wohl — and the evidentials
The middle band is the richest. wahrscheinlich ("probably") is the neutral default; höchstwahrscheinlich ("most probably") is stronger; vermutlich ("presumably") foregrounds that you are guessing. The small particle wohl is the most German of all — it tucks a "probably / I assume" right into the middle field and is the natural spoken way to hedge a claim. Separate from these are the evidentials anscheinend and offenbar ("apparently / evidently"): they do not rate your inner confidence but signal that your statement rests on outside evidence — what you have seen, heard, or been told. That evidential nuance has no clean single-word English equivalent.
Sie ist wahrscheinlich schon zu Hause — es ist ja fast Mitternacht.
She's probably home already — it's nearly midnight after all.
Du bist wohl müde, oder? Du gähnst die ganze Zeit.
You're probably tired, aren't you? You keep yawning.
Anscheinend hat es geregnet — die Straße ist ganz nass.
It apparently rained — the road's completely wet. (evidence-based)
Possible: vielleicht, möglicherweise — and the eventuell trap
Lower down sit the possibility adverbs. vielleicht ("maybe / perhaps") is the all-purpose word; möglicherweise ("possibly") is its more formal twin; unter Umständen ("under some circumstances", often abbreviated u.U.) is a hedgier "possibly"; kann sein ("could be") is a casual reply. Then there is the most notorious false friend in the language: eventuell. It does not mean "eventually" — it means "possibly / perhaps", a near-synonym of vielleicht. English "eventually" (in the end, finally) is schließlich or letztendlich. Mixing these up reverses your meaning: Ich komme eventuell means "I might come", not "I'll come eventually".
Vielleicht hat sie den Termin einfach vergessen.
Maybe she just forgot the appointment.
Wir treffen uns morgen, eventuell auch erst übermorgen.
We'll meet tomorrow, possibly not until the day after.
Möglicherweise wurde die Sitzung verschoben.
The meeting may possibly have been postponed. (formal)
The German specialty: modal verbs for likelihood
Here is the move English speakers most consistently miss. Beyond their "permission / obligation" meanings, German modal verbs have a second, epistemic life in which they grade how likely a guess is. The verb stays the same; only the reading shifts. This is the subjective use of modals (versus the objective use), and reading it correctly is a B2 skill. See objective vs. subjective modals.
- muss — strongest inference. Er muss krank sein = "he must be ill" (I'm drawing a near-certain conclusion from evidence).
- dürfte — high probability, politely hedged. Er dürfte krank sein = "he's probably / likely ill". This is the Konjunktiv II of dürfen used as a probability marker — there is no everyday English single-word match; "is likely to be" is the closest. It is a hallmark of careful, educated German.
- kann / könnte — possibility. Er kann krank sein / Er könnte krank sein = "he might / could be ill". könnte (Konjunktiv II of können) is softer and more tentative than kann.
- mag — concessive possibility, somewhat literary. Er mag krank sein, aber … = "he may well be ill, but …" — granting the point while heading somewhere else.
Das Licht brennt noch — er muss also noch im Büro sein.
The light's still on — so he must still be in the office. (strong inference)
Bei dem Verkehr dürfte sie sich um eine halbe Stunde verspäten.
In this traffic she's probably going to be half an hour late. (dürfte = likely)
Das könnte stimmen, aber ich bin mir nicht ganz sicher.
That could be true, but I'm not entirely sure.
Er mag recht haben, trotzdem überzeugt mich das Argument nicht.
He may well be right, yet the argument doesn't convince me.
Futur I for a present assumption: Er wird wohl …
The other German-specific tool is the Futur I (werden + infinitive) used not for the future at all, but to assume something about the present. Er wird (wohl) zu Hause sein means "he's probably home (right now)", not "he will be home". The future form, often reinforced with wohl, signals a confident inference about a current situation. English speakers expect werden to mean "will" and so miss this reading entirely. The same construction works for the past with Futur II: Sie wird es vergessen haben = "she'll have forgotten it / she's probably forgotten it". See Futur I.
Wo ist Tom? — Keine Ahnung, er wird wohl noch schlafen.
Where's Tom? — No idea, he's probably still asleep. (Futur I = present assumption)
Das wird schon stimmen, da mache ich mir keine Sorgen.
That's probably right, I'm not worried about it.
Sie antwortet nicht — sie wird das Handy stumm geschaltet haben.
She's not answering — she'll have put her phone on silent. (Futur II = past assumption)
Doubt and exclusion: Ich bezweifle, dass …, wohl kaum, auf keinen Fall
At the bottom of the scale you express doubt or rule things out. Verbal frames such as Ich bezweifle, dass … ("I doubt that …"), Ich bin nicht sicher, ob … ("I'm not sure whether …") and Ich glaube nicht, dass … push the doubted content into a verb-final subclause introduced by dass or ob. The adverb wohl kaum ("hardly / surely not") is a tidy spoken way to dismiss a guess, and auf keinen Fall / keinesfalls / unmöglich slam the door entirely. Note that ob ("whether") appears with verbs of uncertainty, while dass ("that") follows verbs of belief/doubt. See hedging and softening.
Ich bezweifle, dass er den Zug noch erwischt.
I doubt that he'll still catch the train.
Bis morgen schaffen wir das wohl kaum.
We'll hardly manage that by tomorrow.
Ich bin mir nicht sicher, ob das die richtige Adresse ist.
I'm not sure whether that's the right address.
Das macht er auf keinen Fall, das passt gar nicht zu ihm.
There's no way he'd do that, it's totally unlike him.
Word order: where the probability word goes
A practical note that decides whether your hedge sounds native. Sentence adverbs of probability (wahrscheinlich, vielleicht, bestimmt, wohl) sit in the middle field, typically right after the finite verb and the subject pronoun: Sie kommt wahrscheinlich später. You can also front the adverb for emphasis, which forces verb-second (V2): Wahrscheinlich kommt sie später — note the verb still comes before the subject. The tiny particle wohl, by contrast, almost never fronts; it lives quietly in the middle (Sie kommt wohl später). Putting a probability adverb in the wrong slot is a common and audible B2 slip.
Vielleicht regnet es morgen, vielleicht auch nicht.
Maybe it'll rain tomorrow, maybe not. (fronted vielleicht → verb second)
Er hat das wahrscheinlich gar nicht gemerkt.
He probably didn't even notice. (adverb in the middle field)
Common Mistakes
❌ Ich komme eventuell um acht — also, ich komme bestimmt, nur etwas spät.
Self-contradicting — 'eventuell' means 'possibly', not 'eventually'. It signals you might NOT come.
✅ Ich komme vielleicht um acht. / Ich komme schließlich doch noch.
I might come at eight. / I came in the end after all.
❌ Er wird zu Hause sein, weil sein Auto draußen steht. (meaning: he's probably home now)
Risk of being misread as future 'he will be home'; add 'wohl' to flag a present assumption.
✅ Er wird wohl zu Hause sein, sein Auto steht ja draußen.
He's probably home, his car's parked outside after all.
❌ Er muss vielleicht krank sein.
Contradictory — 'muss' is strong inference, 'vielleicht' is weak possibility; don't combine them.
✅ Er könnte krank sein. / Er muss krank sein.
He might be ill. / He must be ill. (pick one level)
❌ Ich bezweifle, dass er kommt nicht.
Wrong — in a 'dass'-clause the verb goes last, and don't double the negation: 'dass er nicht kommt'.
✅ Ich bezweifle, dass er kommt. / Ich glaube, dass er nicht kommt.
I doubt he'll come. / I think he won't come.
❌ Wahrscheinlich sie kommt später.
Wrong word order — a fronted adverb forces verb-second: 'Wahrscheinlich kommt sie später'.
✅ Wahrscheinlich kommt sie später.
She'll probably come later.
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Start learning German→Related Topics
- Objective vs Subjective Use of ModalsC1 — How the same modal verb carries two layers — real ability/obligation (objective) and the speaker's inference or hearsay (subjective/epistemic).
- Futur I: Future and Probability with werdenB1 — How to form the Futur I with werden plus an infinitive, and why it more often signals probability about the present than the actual future.
- Sentence Adverbs (leider, vielleicht, hoffentlich)B1 — Adverbs that comment on the whole sentence — leider, vielleicht, wahrscheinlich, hoffentlich — including why fronting them still forces verb-second inversion and how hoffentlich packs 'I hope that' into one word.
- Hedging, Softening, and VaguenessB2 — How German softens a claim with one Konjunktiv II form instead of stacked English qualifiers — plus the high-frequency false friend that trips up every learner: eventuell means 'possibly', not 'eventually'.
- Konjunktiv II: Hypotheticals, Wishes, and PolitenessB1 — The German mood for the unreal — hypotheticals, wishes, and the everyday politeness behind hätte gern, könnten Sie, and würden Sie.
- dürfen: Permission and ProhibitionA2 — How to use dürfen for permission, prohibition (nicht dürfen = 'must not'), polite offers, and the dürfte probability marker.