for us is tricky. "They took everything for us" would imply at least in my mind, that we now have the things, we just didn't do the taking. Then, the translation would be "Vzali všechno za nás". This would be then more accurately translated into "They took everything instead of us", which is I think synonymous wit "for us".
I didn't get it at all(hope, there would be tips in next version):
1) In "Naše rodiče nám pomahaji", "nám" means "for us"("we" is a target)
2) In "Vzali nám všechno" "nám" means "from us"("we" is a source) How one should distinguish these two usages? How to understand, if any particular "nám" is used as source, or a target in a sentence?
P.S. Does "jí" in "vzal jí sklenici z ruky" works in the same way(source of an action), as in 2?
Note: "naši rodiče"
Various verbs use various direct and indirect object. You have to learn each of the separately, the same way we have to learn the large list of English phrasal verbs.
nám - dative, literally "to us" or "for us" or "from us", but you have to check each verb separately
"Vzali nám všechno." can also mean they took it for us and brought to us. But it is more likely used fir some specific objects, rather than všechno.
Thank you very much for an explanation an a note!
What is the best way to learn these verbs? Are there some usage lists, or rules of thumb or something?
If I get this right, phrase "Vzali nám nůž" may mean both "They took a knife for us" and "They took a knife from us". Are there any common ways to solve this collision among Czech speakers or it is always should be made clear through context?