He should have been given the boot years ago.

can you be clearer on why you think "should give" should be able to replace "should have been given"?

"should have" is used to refer to past events that did not happen, not prophecies, commands, or orders.
"I should have taken the job, but i didn't, so I feel stupid." The "should have" in this sentence cannot be replaced with "should take."- for , i assume, fairly obvious reasons..

Thanks.

But SHOULD HAVE DONE STH is not necessarily used to tell something that was possible but did not happen. As for the sentence being discussed, we don't know whether the thing was done or not.

The modals like "shall" and "can" do not really have a past tense. "Can" and "could" may sometimes work that way, but not the others. If the sentence was "We can give him the boot", you could make that into a sort of past-tense sentence with "We could give him the boot", but even that is unreliable, since the sentence with "could" is liable to be understood to mean the same thing as the one with "

"Should have" is used exclusively to refer to things in the past that you ought to have done, or might have done, but (at the time) didn't. You could, of course say, "I fired him last week, but I should have fired him years ago." In this sentence, the action of firing occurred, but in the opinion of the speaker, it occurred later than it ought to have done. I honestly don;t know of any other uses

Thanks for the reply.

I can't check whether you are a native English speaker, but it's not that important now.
I've come to learn English, not to argue. I'm tied up with my studies, so I'm not going to give an exhaustive explanation as to how SHOULD HAVE DONE STH can be used. It has more functions than you think; you ask fivejedjon, he will tell you this is not the exclusive usage.

Hi johnson, I am a native speaker, and I'm not trying to argue with you, i apologize if it came across that way. I'm simply curious as to what other ways you think "should have+pp" can be used other than the way i just explained. I simply asked what other ways you think it might be used so that, if you had any misapprehensions like with the sentence you originally posted, i could perhaps help you

Thanks.

Does it mean constructions like modal+have+ed/en form are used to disambiguiate the sentence?

A sentence: it would have been reasonable for the government to assume the uni wanted the second site.

If WOULD BE is used, it can also mean a present situation as a stand-alone sentence without the protasis, right?

He should have been given the boot years ago.
Should give cannot replace should have been given in your sentence.

As for the sentence being discussed, we don't know whether the thing was done or not.
We do know it was not done years ago. T

Hi Blue jay. Yes, that is another usage, you're right - to say something ought to have occurred, and probably has. Slipped my mind the first time (apologies Johnson13). But i think that exhausts it's usage...

Thanks all.

I've said I'm taken up with my work; but since this is requested by Blue Jay, I should spend some time to type an answer.

Even in modern English, there are at least three usages for SHOULD HAVE DONE STH, one being to show strong emotion.

Scottish writer JM Barrie has a line in his play: Odd that they should not have presented you with a copy.