What, like no other language ever uses more than one word to describe the same thing? Of course there are rules. Maybe more or less strict than other languages, but without rules everyone would sound like a postmodern novel and no one would know what the heck anyone else was talking about.
I have a bilingual reproduction of something from 1500s English translated into 1500s Spanish. Spain has had an important language academy for many years which has determined what changes will be allowed in the language. I found it was easier to read and understand the Spanish than the English because it was more like modern Spanish.