if something determines something else, it directly influences or decides it The amount of available water determines the number of houses that can be built. The age of a wine is a determining factor as to how it tastes.
就你说的两个例子说吧。现有的水量决定了能建的房子。是指水量限制了能建多少房子,多也多不了。因果是某件事的产生是另外一件事导致的。你可以用TO BE THE CAUSE代替该动词,看看对不对。The amount of available water is the cause of (determines) the number of houses that can be built.这句话显然是行不通的。另外一个例子也一样。