Expected primary-Expression before 'sonic'

You have go to post the full compiler results: No where do no mention what processor your are using?

You have some syntax errors in your code:

Servo sonic; creates the object, do not type cast the (int)

Then you have distance = Servo sonic.read();

Do not put the object type of Servo on the same line as the read().

distance = sonic.read();

Here is an example:

Arduino Servo example