[1] The term language is frequently used as a synonym for a sign-system.
In traditional forms of face-to-face communication, humans communicate through non-verbal as well as verbal sign-systems; colloquially, this can be referred to as body language.
Hence, humans communicate a great deal by way of facial movements and other forms of bodily expression.
Tone of voice in spoken communication, conveys meaning.
Depending on tone, a phrase can have several meanings; e.g. "you like that" can mean the speaker believes the listener likes something, or it can be a question, or it can convey disbelief.