know something by heart/ learn something off by heart
umět/naučit se něco nazpaměť
But he had written his book - the people in Glasgow and Paisley knew it by heart, nearly -- now it was up to themselves.
I once knew by heart a poem by the Russian, Fyodor Tyuchev entitled Vyesna (Spring). It began: Already in the fields.................
As presentation day grew closer with Mark racing against time to complete the plan and finalise the slide illustrations, so Klepner read and re-read it until he had almost learnt it off by heart.