Breakdown of Du musst das Kassenbuch täglich prüfen.
du
you (informal singular)
müssen
to have to, must
täglich
daily
prüfen
to check / to test
Questions & Answers about Du musst das Kassenbuch täglich prüfen.
Why is there an -n- in the middle of Kassenbuch?
Kassenbuch is a compound noun made of die Kasse (cash register or checkout) and das Buch (book). When the first noun in a compound is feminine and ends in -e, the linking element (Fugenlaut) is almost always -n-.
Does the -n- mean that Kassenbuch refers to multiple cash registers?
No. While it looks exactly like the plural form (die Kassen), in this compound it acts purely as a linking sound. The book is typically just for one cash register, but the -n- makes the two words flow together more naturally without awkward vowel repetition.
Why doesn't täglich have a grammatical ending here?
Because it is being used as an adverb to describe how often you must check (prüfen). In German, adjectives acting as adverbs do not take any declension endings, regardless of the case or gender of surrounding nouns.
What is the difference between prüfen and kontrollieren in this context?
Both translate to "check" and can often be used interchangeably. However, prüfen implies a slightly more thorough, methodical examination or audit, which fits perfectly when dealing with a financial record like a Kassenbuch.