Gisteren regende het zo hard. IT RAINED SO HARD YESTERDAY (Past Simple)
Oh ja. Ik zie het. Het heeft heel hard geregend. OH, YEAH. I SEE. IT HAS RAINED VERY HARD. (Present Perfect) (always, never, ever, yet, already, just, for, since)
Het had al hard geregend toen ik thuis kwam. IT HAD ALREADY RAINED WHEN I CAME HOME. (Past Perfect)