Past Progressive/Continuous tense

Progressive or continuous tenses tell you what is/was or is going to be happening at a specific moment in time.

We are going to focus on the past continuous in this mini lesson. To conjugate it, we need 2 separate verbs. The first is referred to as the auxiliary verb – for progressive/continuous tenses this verb will be “estar”. We are going to use the imperfect tense of estar.
E.g. estaba, estabas, estaba, etc.

The second verb will be a gerund. This is the “-ing” ending form of the verb in English.
For regular -AR verbs you remove the -AR and add “-ando”.
For regular -ER and -IR verbs you remove the -ER and -IR and add “iendo”.

For irregular verbs: Verbs ending in -er and -ir with a vowel before the ending, i.e. -aer, -uir, -eer, oir. We exchange the ‘i’ in -iendo for a ‘y’. E.g. creer = creyendo.
 
The verb “ir” meaning ‘to go’ is completely irregular and becomes ‘yendo’.

For stem changing verbs (in the present tense) that follow an e > i or e > ie stem change, swap the ‘e’ for an ‘i’ and add the regular gerund ending. E.g. preferir = prefiriendo.
For stem changing verbs (in the present tense) that follow an o > ue stem change, swap the ‘o’ for a ‘u’ and add the regular gerund ending. E.g. dormir = durmiendo.

For -IR verbs that have a vowel change ‘e > i’ and that have an -e immediately before the -ir lose the -e from the stem. E.g. reir = riendo.

E.g. Estaba haciendo mi tarea – I was doing my homework.
Estaba pensando – I was thinking.