If my knee has been bothering me for years and it hurts when i put weight on it and do activities do i have a torn ligament? it has been bothering me since 8th grade i am 19 now

Ligaments : Ligaments connect bone to bone and at your age you would likely remember if you tore one. Other more probable causes would include inflammatory issues or possibly a cartilage injury. Further evaluation from an orthopedic specialist could not only help diagnose the problem, but also provide treatment recommendations.

Knee pain: Because your symptoms have been present for this long, you should see a physician. They will be able to examine your knee and come to a diagnosis. He/she will develop a treatment plan for you as well. Best of luck!

Many possibilities: See a sports med doc for exam. Often a personalized course of physical therapy can be helpful, regardless of the cause. The therapist will look at your individual mechanics and make recommendations for proper alignment. There are multiple other treatments if that doesn't resolve the symptoms completely.