Preposition and adverb

[Khamala]

I went up on the hills.
They live up in the mountains.
It threw water up into the sky.
In 3 cases, can I turn "up on/up in/up into" into "up" (prep)? If not, what's the difference?

 

[emsr2d2]

1. I went up on the hills.
2. They live up in the mountains.
3. It threw water up into the sky.

In all 3 three cases, can I turn change "up on/up in/up into" into "up" (prep)? If not, what's the difference why not?

Sentence 1 isn't natural as written.
If you change "up in" to "up" in sentence 2, you change the meaning and would end up with an ungrammatical sentence.
Sentence 3 would be ungrammatical if you removed "into".

 

[Khamala]

up (prep) = to or in a higher position somewhere
So why they use up (adv) + another preposition?

 

[jutfrank]

You can use up as a head of a preposition phrase when you want to express a sense of movement:

I went up the hill.
We hiked up the mountain.

We also use it to express the direction of a certain location:

She lives up the street.
They're from up north.