Because the preposition v means in or inside, and when it expresses location, the following noun normally goes into the locative case.
So tašce is the locative singular form of taška.
Krmivo usually means feed, animal feed, or sometimes pet food, depending on context.
It is not the usual word for food for people. For human food, Czech uses words like jídlo or potrava in different contexts.
So if you see krmivo, think of food meant for animals.
Taška is a fairly general word for bag. It can refer to things like:
But Czech also has more specific words, for example:
So taška is broad, but not the only word for bag.
Yes, Czech word order is more flexible than English word order.
Krmivo je v tašce is a neutral way to say it.
You could also say:
Both are grammatical, but they may shift emphasis slightly:
Krmivo is neuter.
You can often recognize many neuter nouns by endings like -o or -e, though not always.
It matters because gender affects:
In this sentence, there is no adjective, so you do not see much effect yet, but it is still useful to know that krmivo is neuter.
Yes. Since Czech has no articles, v tašce can mean:
Context tells you which is meant.
A simple yes/no question is:
In Czech, you often form a question just by intonation or by putting the verb first.
So compare: