I suggest you ask your teacher to clarify exactly what (s)he means by this question. I’m not entirely sure what (s)he is asking for. I will describe below two possible interpretations of the question BUT they might be different to what your teacher wants.
By tone, your teacher could be referring to tone of voice. So, a harsh, authoritative tone would elicit a different reaction from a gentle, encouraging tone of voice. If this is what is required, you could describe the above and suggest how teens would react to encouraging and authoritative tones of voice.
Alternatively, tone could refer to sociolinguistic or psycholinguistic aspects of language. For example, compare these two questions:
Your last sentence is wrong, what is the correct form? and
There’s something not quite right in your last sentence. Could you try to correct it? Could anybody try to correct it?
Please ask your teacher what exactly is needed and write in again with his/her explanation. I will be happy to give you more ideas for this assignment.