Learn Spanish (Latin America): Me duele la rodilla.

In Spanish, when talking about body parts, you almost always use the definite article (el, la, los, las) instead of possessive words like mi (my). Because the sentence starts with Me (to me), it is already obvious whose knee is hurting.

How does the verb doler work here? It feels backward compared to English.

Doler (to hurt or ache) works just like gustar. Instead of saying 'I hurt my knee', Spanish phrases it as 'The knee causes pain to me'. La rodilla is actually the subject doing the action, which is why the verb duele matches it, and Me tells us who is feeling the pain.

Why is the verb spelled duele and not dole?

The dictionary form of the verb is doler, but it is a stem-changing verb. This means the o in the middle changes to ue when conjugated. Since la rodilla counts as an 'it' (a single thing), we use the changed form duele.

How would this sentence change if both of my knees hurt?

You would make both the verb and the noun plural: Me duelen las rodillas. The pronoun Me stays exactly the same because the pain is still happening to you, but now multiple knees are doing the hurting!