Student or Learner
Could I say "take some water"?
I see water is uncountable noun. And if we can say like that. How does its meaning change?
Neither do I, but in certain contexts you can say, "Take some water".
So, when we use "take some water". What may we want to imply?
You are suggesting someone to drink water. It's sort of an offer.
Not a teacher.
If someone is going out for a walk on a hot day, you might say, "Take some water", i,e., you are suggesting that they take a bottle of water with them so that they can have a drink when they get thirsty.