can and is able to

[littlebaby]

hello,

I want to ask what's the difference between can and is able to?

[Mister Micawber]

.
Mostly, can has no future tense and a confusing past tense (could).

I can dance.
I will be able to dance.
I was able to dance.
I could dance. (in the past? if I wanted to now?)
.