The Spanish imperfect tense in Spanish occurs (in my observation) only twice. It can be found in the words pensaba and estaba. These two words are probably one of a handful verbs in Chabacano which are conjugated. Note however that only these two forms exists (pensabas, pensaban, & etc. and estabas, estaban, & etc. do not exist).
Here are some examples on how Chabacano uses the word pensaba:
Pensaba yo hide tu ta come carne
I thought you don't eat meat
Pensaba le ya mori ya tu
He thought that you already died
Pensaba mio nana volve* tu este diciembre
My mother thought that you will come home this december
*The word volve in spanish means to go home (a casa is ommitted).
As you may have noticed Chabacano pensaba is similar to Spanish pensaba. The Chabacano usage of estaba also seems to be similar to that of its Spanish meaning. Here are some examples:
Estaba yo alli
I was there
Estaba mio nana na pueblo
My mom was in the downtown
Estaba yo na casa de mi hermana
I was at my sister's house
Note that the english translations were done this way to show similarities to Spanish. In reality, Chabacano estaba literally translates to (subject) came from. It is used when speaking about being in a certain place in the past. It can also be substituted with the words ya anda. Examples are:
Ya anda yo alli
Ya anda mio nana na pueblo
Ya anda yo na casa de mi hermana
Ya anda literally translates to (subject) went to.