Learn Dutch: Ik heb me vaak afgevraagd of hij komt. - I have often wondered if he is coming.

The verb is zich afvragen (to wonder), which is a reflexive verb. In Dutch, all reflexive verbs form the present perfect tense using the helper verb hebben, never zijn.

How does the word afgevraagd get its shape?

The infinitive is zich afvragen. Because it is a separable verb (af + vragen), the ge- part of the past participle goes right between the prefix and the main verb. That gives us af + ge + vraagd.

Why does me come before vaak?

Reflexive pronouns like me (myself) generally stay right next to the conjugated verb, which is heb here. Words that describe time or frequency, like vaak (often), come after the reflexive pronoun.

I thought of meant "or". Why does it mean "if" here?

The word of can mean both "or" and "if" (or "whether"). When it introduces a dependent clause like of hij komt (if he is coming), it means "if". As a connecting word, it also pushes the verbs in its clause to the end, though here there is only one verb anyway!