"I drink that water."
Translation:Saya meminum air itu.
Following is the explanation from a native teacher who is a Indonesian teacher :) [note that I am also a native speaker]
"minum" may be followed by object and may not be. Whilst, "meminum" must be followed by object.
Saya minum air.
Saya meminum air.
We cannot say, "saya meminum".