Questions & Answers about Iemand verstopt iets in zijn zak.
Why does iemand take the singular verb verstopt?
Just like 'someone' in English, the indefinite pronoun iemand is always treated as a singular subject. Because of this, the verb takes the third-person singular form (stem + t): verstopt.
Why do we use zijn (his) to refer back to iemand? What if the person is female?
In Dutch, iemand is grammatically masculine. When you need a possessive pronoun to refer back to it, you default to zijn (his), even if the gender of the person is unknown or could be female.
I learned that zak means 'bag'. Why does it mean 'pocket' in this sentence?
The word zak is used for both 'bag' (like a plastic bag) and 'pocket' (which is technically broekzak or jaszak). The context here tells us it means pocket, since you usually hide small things in your clothing.
How would this sentence change if I wanted to say 'Nobody is hiding anything'?
You would change iemand to niemand (nobody), but keep iets (something/anything). The sentence becomes: Niemand verstopt iets in zijn zak. Dutch does not use double negatives, so saying niemand and niets together would technically mean 'nobody is hiding nothing'.