FORM Time Signal
Past : 1 . Simple : S+V2+C yesterday
2 . Continue : S+Was/Were+V(ing) when/while
3 . Perfect : S+had been+V3 last
4 . Perfect Continues : S+had been+V(ing) a long time ago
Present : 1 . Simple : S+V1+s/es every
2 . Continue : S+to be (are,is,am)+V(ing) now
3 . Perfect : S+have/has+V3 already
4 . Perfect Continues : S+have been+V(ing) just
Future : 1 . Simple : S+will/shall+V1 tomorrow
2 . Continue : S+will/shall+to be+V(ing) next
3 . Perfect : S+will/shall+have+V3 latter
4 . Perfect Continues : S+will/shall+have been+V(ing)