Er muss krank sein: when the modal is not an order but a guess
CEFR B2 · part 1
edumaterial's parts within the level. The European framework does not subdivide them.
The passive in the past and with modals: wurde gebaut, muss gemacht werdenTaking the passive into the tenses that were missing. In the Präteritum only werden…Die Tür wird geöffnet or ist geöffnet: the action and the stateTelling apart two sentences that look alike and mean different things. Die Tür wird…Er sagte, er sei krank: the Konjunktiv I of the newspapersReporting what somebody else said without making it yours. German has a verb form just…Der gestern von uns gekaufte Tisch: a whole clause wedged inside the articleReading —and taking apart— the construction that makes German technical prose look…dennoch, folglich, hingegen: the connectors of written GermanThe connectors that make a text read as if an adult wrote it: dennoch for concession…bestehen aus, auf or in: when the preposition changes the meaningThe advanced tier of prepositional verbs: the ones with SEVERAL prepositions that mean…The rule, in three lines
The modals' second job, the one the dictionary never mentions. Er muss krank sein is not an obligation: it is «he must be ill», meaning I am sure. And there is a whole scale: muss is certain, dürfte likely, könnte possible, kann nicht impossible. Plus two that say who is doing the claiming: er will is «he says so himself» and er soll is «others say so».
The usual slip. Reading every modal as obligation or permission, so «he has to be ill» comes out as an absurd order. The signal that the modal is guessing is a stative infinitive —sein, haben, wissen— or a past infinitive: Er muss krank gewesen sein. And the pair that fools everyone: er will reich sein is «he claims to be rich», er soll reich sein is «he is said to be rich».
Why it catches you out. English does all of it —«he must be ill», «he might be», «he can't be»— with the very same verbs. This is the most transferable unit in B2.1. The genuinely new things are er soll and er will as reporting devices, where English needs «is said to» and «claims to».