One of the most important areas in the study of a language is the syntactic rule. These rules govern the patterned relations of words that are combined to form phrases and the phrases again combined to form sentences.
Even the writer who is writing this answer is able to convey his thoughts to you because of the syntactic rules. A sentence written in a particular way conveys a certain thought to you but if the writer conveys those very thoughts in some other way which you don't understand or which is not universal, probably you will end up throwing the page as it is not serving your purpose.
It is for this very reason linguists form the rules that can govern the language universally and anybody without universal acceptance does something else will not be able to convey his thoughts.
Even the writer who is writing this answer is able to convey his thoughts to you because of the syntactic rules. A sentence written in a particular way conveys a certain thought to you but if the writer conveys those very thoughts in some other way which you don't understand or which is not universal, probably you will end up throwing the page as it is not serving your purpose.
It is for this very reason linguists form the rules that can govern the language universally and anybody without universal acceptance does something else will not be able to convey his thoughts.