Where did you come from? Where did you go? Where did you come from kattene Joe?
So... -er is plural, -ene is plural with "the"?
That's right! You'll often see the former referred to as the indefinite plural, and the latter as the definite plural. :)
Just beware that the neuter nouns follow a different declination pattern.
Why not: We love cats?
That would be vi elsker katter. _Kattene_is the definitive form:the cats
Are the two Ts silent?
Double Ts are barely pronounced when they are followed by -ene or -ende