Are there irregular verbs in the imperfect progressive tense In Spanish?

You're right to question that! Spanish doesn't have a true "imperfect progressive" tense like English.

Instead, we use the imperfect tense combined with the present participle (the "-ando/-iendo/-yendo" form) to express continuous or ongoing actions in the past.

For example:

* English: I was studying.

* Spanish: Yo estaba estudiando.

Here, "estaba" is the imperfect tense of "estar" (to be), and "estudiando" is the present participle of "estudiar" (to study).

Irregular verbs in the imperfect tense are still irregular, but the present participle remains regular.

For example:

* English: You were coming.

* Spanish: Tú venías.

Venir (to come) is irregular in the imperfect, but the present participle "viniendo" remains regular.

So, while there isn't a specific "imperfect progressive" tense in Spanish, irregular verbs still play a role in creating the sense of continuous past action by being irregular in the imperfect form.