What is the difference between の and が? Is there any difference between の and が particles in phrases like 背が高い （背の高い）, 雨が多い （雨の多い）, etc? I've seen both of them in similar sentences and can't catch any regularity of where and which one I should use. For example, are these sentences the same: あの人は背が高いです。 <-> あの人は背の高いです。 人口が多い国です。 <-> 人口の多い国です。 Thanks.