If we say
Jim is to be at the party tomorrow.----Means he is due to go.
It now party time and we all friends are at the party and party is going on and someone asks where is jim? I would say
Jim was to be at the party now, but I don't know whether he has come,but he was to have come by now.-------Means jim was expected to be at the party and since the party is not over we must use 'was to' [base form] and not 'was to have' [past participle].The time now under consideration is well past the arrival time so we say 'He was to have come', say by 7:00pm,But it is now 8pm.
Now the party is long over its been days since it got over then if someone asks me was jim at the party,Then I would say this
Jim was to have come and was to have been at the party, he did come eventually.-------Meaning here I use 'was to have come' [past participle] as the chance to come to the party is over and the party itself is over.So I must use this form.
I can also use 'was to have been' in one more way.Like party has started and it's been two hours since it began.Now if someone comes and asks me where is jim.I would say
Jim was to have been at the party for two hours by now, and was to be till the end of the party.----Meaning at the time we were talking two hours had passed so we used past participle for those two hours and base form for the rest.
If the above is correct then it means we can use the past participle with "by now" also.AM right?
And one more If I say
Jim was to be at the party by now.Would this mean the same as Jim was to be at the party by now?
So Please tell me whether I am right about all this interpretation?
Please I will be thankful to you all.I have thought for many many hours now about this.