help!

[chum]

I read this sentence from a business English book...it says " I should have finished my work by Friday" , which confuse me because the first time I read it, it gave me an idea that the action will take place in the future...but i know that "should have + PP" is used in the past, but I usually use "by Friday" for future events. Could you explain this to me.



Thanks a lot!

[DavyBCN]

I read this sentence from a business English book...it says " I should have finished my work by Friday" , which confuse me because the first time I read it, it gave me an idea that the action will take place in the future...but i know that "should have + PP" is used in the past, but I usually use "by Friday" for future events. Could you explain this to me.
Thanks a lot!

The future perfect tense is used to look forward to a point in time and say/predict what actions will have finished by that future time, using the structure will + have + past participle.

You can, however, replace will with some other modal verbs to indicate your view of how likely your prediction is - I should/may/ought to to have finished my work by Friday.

[Humble]

Hello, Chum,
I think the sentence is ambiguous without additional context: it may refer either to the past or to the future.
a)I should have read the book by (last) Friday - the person who gave me the book, asked me to return it by Friday, but I didn't.
b) I should do it within the time that ends on Friday -in the future, and by requires the Perfect.
By can be used in the past:
We had learned 50 phrasal verbs by the end of school term.
Regards