My ankle started swelling & now feels like it is broken. other than an xray how can i tell?

You, as : A patient, can't. See an orthopedic surgeon and, if he/she thinks its needed, obtain an xray.

See the doc: Go to a foot/ankle specialist to get a proper exam. Your doc will physically examine the ankle to check range of motion and localized pain. Xrays with highlight alignment and check for fractures, but if necessary, an MRI would reveal both bone and soft tissue damage.

Swollen ankle: Have you had an x-ray taken? Sounds like you need to have a complete history physical examination and lower extremity evaluation for foot function. It also sounds like you could possibly need orthotic therapy, or some type of immobilization. See a podiatrist.

Scans: Mri, ct scan and bone scan are other options but always start with xray.