The Present Progressive Tense is the "ing" of English - I am eating, she is playing,
We are walking, etc. Although it's a completely different tense,
there's a very simple formula to conjugating the present progressive.
It is as follows:
Estar + present participle
The form of estar needs little explanation: You simply conjugate it based on the subject.
For example, if I wanted to say "I am eating", I would choose "estoy" since I is the subject,
and then choose whatever the present participle of eating is, which, let's actually figure
out now.
The process is simple for creating the present participle of regular verbs:
There are two different cases of irregular verbs for the present progressive: double vowel verbs and stem-changers.
This, too, is a very simple process. If the last letter of the stem (in other words, the letter right before the ending) is a vowel, you simply follow this process to create the present participle:
IR Verbs that stem change from E:IE or from E:I only stem change from E:I for the present participle. Similarly, IR verbs that stem change from O:UE only stem change to O:U.
Any weird verbs?
Yes! They are three worth noting:
Ir = yendo
Seguir = Siguiendo
Poder = Pudiendo (only ER verb)