What is the proper tense for "listen" in this sentence?

The past tense of "I listen to a particular podcast" when the present tense "listen" conveys action the subject does habitually is:

• "I used to listen to a particular podcast."

I teach ESL to Spanish and Portuguese speakers. In Spanish and Portuguese, speakers use the past imperfect tense for conveying habitual actions in the past, which commonly results in my students mistakenly using the past progressive tense in English by saying, for example, "I was listening to a particular podcast."

Well, anyone who speaks English as their first language knows that "was listening" is not how to convey that habitual action in the past, thus my lesson on how "used to" is used to form the past imperfect tense in English, what with English not having an actual verb tense devoted to this in the same way Spanish and Portuguese does, which if English did, the sentence would look something like, "I listeneda to a particular podcast." But I digress.

How you would say your last sentence to convey the past imperfect notion of the subject's action done habitually in the past is:

• "There was a guest on a podcast I used to listen to."

As there seems to always be more than one way to skin a cat in English, other ways of conveying this include:

• There was a guest on a podcast I would listen to.

• There was a guest on a podcast I always listened to.

Reference:

Habitual (repeated) action in the past can be marked by used to, as in "I used to eat a lot", or by the auxiliary verb would, as in "Back then, I would eat early and would walk to school." (The auxiliary would also has other uses, such as expressing conditional mood.) However, in many cases the habitual nature of the action does not need to be explicitly marked on the verb, and the simple past is used: "We always ate dinner at six o'clock." (https://en.wikipedia.org/wiki/Imperfect#English).

It's present tense, but in linguistics, we would assign it the habitual aspect. Present tense verbs can be used to describe habitual behavior in English, and in fact, this usage is very common.

He plays chess. She eats anchovies. Her friends thinks anchovies are gross.

All use the present tense verb and express habitual behaviors.