What are characteristics of formal language?

Characteristics of Language:

1) verbal, vocal & sound

2)social phenomenon

3)means of communication

4)non-instinctive, conventional

5) arbitrary

6)symbolic

7)systematic

8)unique

9)linguistic & communicative competence

10)human & structurally complex

If we are talking about language, and something that looks like language but is not… the important characteristic is "7)" - being bound by rules. The core principle is that you can use a language to make new sentences (and other people will understand you). This is (only) possible because language has rules for making sentences, by putting words together systematically. (Of course, it is possible to be understood without constructing a proper sentence - Gen Y's do it all the time.)