I suppose he's serious, ________ ?

proper nouns

disjunct

putative should

subjunctive mood

What is the system of two tenses and two aspects?

List two types of subjunctive mood.

Using modal auxiliary:

He was the last person to commit the embezzlement.

Using cleaving for time adjunct:

I got the invitation last week.

Using an exclamation:

She has a beautiful hat.

Using extraposition:

What they are proposing to do is horrifying.