School and learning idioms: erin vliegen (to fly into something — to fall for a trick/to make a naive mistake in a test), door de mand vallen (to fall through the basket — to be exposed, to have your bluff called), blokken voor een examen (to cram for an exam — blokken means to block, implying dense intensive study), zijn huiswerk doen (to do your homework — both literal and figurative: prepare properly), iets van buiten leren (to learn something by heart — van buiten means from the outside, i.e., memorised).
Intelligence and understanding idioms: een harde noot om te kraken (a hard nut to crack — a difficult problem), de knoop doorhakken (to cut through the knot — to make a decision on something difficult), erin bijten (to bite into it — to tackle something difficult), licht opgaan (the light goes on — to have an aha moment, to suddenly understand), het kwartje valt (the quarter drops — the penny drops, suddenly understanding something), boven de pet gaan (to go above the cap — to be above someone’s comprehension level).
Knowledge and wisdom idioms: de wijsheid in pacht hebben (to have wisdom on lease — to think you know everything, often said ironically), weten hoe de vork in de steel zit (to know how the fork is in the handle — to know how things really work, to understand the true situation), met twee maten meten (to measure with two measures — to apply double standards), horen, zien en zwijgen (hear, see and be silent — to mind your own business). These idioms appear in school contexts, work discussions, and anywhere Dutch speakers discuss knowledge and decision-making.