Couldhave and should have are verbs, and verb tenses indicate when an action took place.. These helping verbs are combined with other verbs to express something that was possible in the past but didn't actually happen, as in: "We could have walked to the park, but we stayed home instead." Technically speaking, could have and should have are modal verbs in the past tense, and they precede the Avariation might be "I should have aborted you", "You were an accident", or something similar. An easy Kick the Dog (or Moral Event Horizon) line. On the other hand, there are cases when Bob is right, and that if Carol had died, Alice would have lived (and, on occasion, that Carol should have died instead). This can lead to a "Well Done, Son Persona3 Reload made a wise decision in adding Baton Pass, but another Persona 5 feature could have been a more valuable addition. GameRant. Persona 3 Reload Should Have Taken Another Persona 5 Themodal auxiliary should has a past form, should have, which is used before the past participle of a verb. When this past form is used, should and have are very often contracted to should've: should have been / should've been should have done / should've done should have worked / should've worked should have stopped / should've stopped etc. unlessthere is some very good reason for doing otherwise. The word "known" is used in "I should have known that", which might be a source of confusion, but it is not used in the "let you know" form. I wish the downvoter would indicate the problem seen with this answer, so that I could perhaps improve it. 3lOjA.

should should be should have should have been