Learn Romanian: Emisiunea pe care o urmărești este interesantă. - The program you are watching is interesting.

In Romanian, when the relative pronoun care (which/that) is the direct object of the verb (you are watching the program), it must have pe in front of it. So pe care is the standard way to say "which" or "that" whenever it receives the action of the verb.

Why is there an o before urmărești?

This is a required echo pronoun. When a direct object (like pe care) comes before the verb, Romanian makes you add a tiny pronoun right before the verb to match it. Because emisiunea is a feminine noun, we use the feminine "it" pronoun, o. Literally, the sentence is structured as: The program which you it watch.

I learned that "to watch" is a se uita. Could I say "pe care te uiți" instead?

You cannot use pe care with a se uita. The verb a se uita requires the preposition la (to look at), so you would have to say la care te uiți. The verb a urmări used here means to follow or watch a broadcast, and it directly takes an object, which fits the pe care o structure perfectly.

Why does interesantă end in an ă here?