A review of English verbs...

We have three main "tenses"

- past: uses -ed ending in simple tense

- present:

- future: uses 'will' modal verb

And four main "aspects"

- simple:

- perfect: uses 'to have' verb and -ed ending

- progressive: uses 'to be' verb and -ing ending

- perfect progressive. uses both 'to have' and 'to be' verbs and -ing ending

Beyond this, the sugar is in how the 'to have' and 'to be' verbs are inflected.

Sadly Spanish is very much not 1:1 with this system.