1 There's some water in the bottle.
2 There's water in the bottle.
What is the second one? What's the difference?
In a 500ml bottle:
"There's water..." speaks strictly of existence or nonexistence, regardless of the amount.
"There's some water..."
Some, in reference to uncountable nouns, usually (though not always) ranges from more than zero up to half.
It can also mean more than half, depending on the need. (Example: you have 500ml in a 500ml bottle but require a litre of water.)