Edit: (I apologize if my question does not make sense. English is not my first language)
Hello, I have just started learning English from online resources and I cannot figure out which sentence is correct:
1st: John was hurt; he knew she only said it to upset him. (uses semi-colon)
2nd: John was hurt, he knew she only said it to upset him. (uses comma)
3rd: John was hurt, but he knew she only said it to upset him. (uses comma and "but")
Thanks