for -ar endings: estar + verb minus -ar + -ando (example: I am walking = Estoy caminando

for -er endings: estar + verb minus -er + iendo (example: I am running = Estoy corriendo)

for -ir endings: estar + verb minus -ir +iendo (example: I am lying = Estoy mentiendo)

Now, when you have a reflexive verb (like casarse), you put the pronoun attached to the ando or iendo

So “I am getting married” would be, Estoy casandome. The pronoun, like always, agrees with the subject. One last thing, to keep the pronunciation right, you’ve gotta add an accent. The trick I learned is to count three vowels from the end and put an accent on the third. So it’s Estoy casándome

Hope that helps!

The gerund is formed by taking the infinitive of the main verb, removing the -ar, -er, or -ir, and adding -ando or -iendo.

“Casarse” is a reflexive verb with an enclitic pronoun. (That means the pronoun is attached to the end of the infinitive form of the verb.) The pronoun must be separated and placed before the verb to form the present progressive.

The present progressive tense of “casarse” is thus: pronoun + estar + cas + ando

me estoy casando, te estas casando, (el, ella, Usted) se esta casando, nos estamos casando, os estais casando, (ellos, ellas, Ustedes) se estan casando

Sorry, my keyboard doesn’t have Spanish accents!