03
As is logical, in a question the Subject and the Modal are inverted:
We should have come earlier
Should we have come earlier?
NOTES
It is not possible to say ‘CAN HAVE DONE’ something, but it is possible to say ‘CAN’ HAVE DONE’ something.
It is not possible to say ‘MUSTN’T HAVE DONE’ something, but it is possible to say ‘MUST HAVE DONE’ something.
It is not possible to use SHALL with a Past meaning.
If you want to use OUGHT TO instead of SHOULD, the structure is: