Ok, I'm very confused. Why is this "sestry" and not "sestru" for a single sister?
Form "sestry" is used for - genitive SG (in this sentence) and also nominative PL
Ah, I get it, ptát wants genitive. Is there somewhere (preferably online) a good list of "look up for each Czech verb which case goes with it"?
The verb is ptát se. And it can use eiter genitive - ptát se někoho/něčeho (to ask sb.) or accusative ptát se na někoho/něco (to ask after sb.) (Like in german fragen und nachfragen)
I don't know about such a list, but maybe someone else does.
In other words:
1. ptát se na + acc
2. ptát se + gen
The Tips & Notes for this lesson lists four verbs that govern the gentitive: se boyim, si beru, se ptám, si vážím.
I note that all four take either se or si.
What's the plural genitive? How would you say "he is asking our sisters"?
On se ptá naších sester.