Some things that can help a reader determine how the author feels about a subject is by their tone and mood. Some ways to determine tone and mood is by word choices. Like, for example the subject is on ice cream. I use words like gross, bad, etc to show that I have a negative opinion (or connotation) on the subject. But, if I were to use words like delicious, yummy, etc that would show I have a positive opinion (or connotation) towards the subject. Hope this helps!