9.51 contrasting tense or modality

If you only want to change the verb tense or modality, you use a new auxiliary, with a subject referring to the same person or thing.

• They would stop it if they could.
• How does the Department of the Environment ensure, as it says it must, that the quality of the operation remains high?
• Very few of us have that tremendous enthusiasm, although we know we ought to.
• I never did go to Stratford, although I probably should have.
• ...a topic which should have attracted far more attention from philosophers than it has.