A palavra termina com " ed ", será que é o passado simples?

Notas do episódio

In this audio lesson, you are about to learn the terrible mistake of many students and the list goes to advanced level. The real deal is when the word ends by " ed ". So, should I consider it as simple past tense. Based on my explanation, if you talk about a verb, so it is the simple past tense. Now if it follows this sequence " subject + verb to be + word+ed " so, it is an adjective.