Is there a grammar? ie. a set of rules to form valid sentences in the language

Is there linguistic creativity? ie. you can generate new words to describe things never encountered

Is there metalinguistic reflexion? ie. can you use the language to talk about the language itself?

Can the language allow displacement? i.e. talking about things that are not in the current spacetime point

These are some of the core requirements for a system of communication to be considered a language.