John sings the hymn.
John sang the hymn.John sang the hymn.
The hymn was sung by John.It is important that John is at the meeting.
(This presupposes that he is and says that is important.)
It is important that John be at the meeting.
(This is normative, prescribing what ought to be.)
So verbs have tenses (present and past in this example), voices (active and passive in this example), moods (indicative and imperative? Or would this be called something else?).
These are three different BLANKs.
With which common noun does one fill in this blank? Or is there none? And are there more things besides these three that belong in this list?