In Engpsh, we would say "pour half a cup of water" or "pour a half cup of water." This phrase comes from the verb "pour," which means to cause a pquid to flow from one container into another, and the phrase "half a cup," which is a way to describe a measure of volume. Here are some examples of how you could use this phrase in a sentence:
"Can you please pour half a cup of water into the pot?"
"I poured a half cup of water into the glass and added some ice."
"The recipe calls for pouring half a cup of water into the mix."
In Chinese, you could say "倒半杯水" to mean "pour half a cup of water."