For Spanish verbs, what are all of the instances that it is necessary to use the "ando/iendo" endings?

Answer 1

For the progressive forms:

I'm listening: estoy escuchando.
I'm saying: estoy diciendo.

As adverbs:

I waste energy running: Gasto energía corriendo.

BUT YOU DO NOT USE THE ANDO/ENDO FORMS IN THE FOLLOWING:

As subject:

Smoking is bad for you: Fumar hace mal ("Fumar" is literally 'to smoke')

With the idea of future:

I'm leaving tonight: Me voy esta noche ("Me voy" is simple present).

With a conditional meaning:

Buying two bottles you take three: Si compra dos botellas, se lleva tres (An "IF-Sentence" in Spanish). [NOTE: This use is not considered correct, but it is quite common in adverts]

Answer 2

Present and imperfect progressive.

Estoy caminando.
Estaba caminando.

Answer 3

For present progressive and gerunds.

Answer 4

it is basically "ing" in english. for example, if you are saying i am playing, it translates to - estoy jugando. or i am eating translates to - estoy comiendo.