The diagram shows where the tonsils are. Tonsillitis can occur with many causes of sore throat. Pus on the tonsils is not a sign of bacterial infection. Mononucleosis can cause a severe tonsillitis. The typical cold may cause a sore throat during any part of the illness.
Colds often begin with a scratchy throat up behind the nose.
Severe coughing may also result in a sore throat just from the force of the cough. People with stuffed noses often wake up with sore throats because they breathe dry air through their mouths all night. A humidifier is very helpful for this symptom. Post nasal drip can be very irritating to the throat. If the post nasal drip is due to a sinus infection it may require antibiotic treatment, otherwise, upper respiratory viruses don't respond to antibiotics.