The Category of Mood

Optative, Voluntative, Expectative, Potentialis, Concessive, Dubitative, Irrealis, Subjunctive, Imperative, Adhortative

…
This approach is semantic and does not take the form into consideration:
He may be here (Potentialis).
He may be here, but I don’t want to see him (Concessive).

Subjunctive I, Subjunctive II, Suppositional, Conditional).
Weak points:
The semantic basis is

inconsistent (condition is not modal).
Combinations of modal verbs having pronounced lexical meaning with the infinitive are referred to analytical forms, which is not the case.
Homonymous forms are introduced.
It is not clear why some forms are the forms of different moods if they have the same meaning and similar syntactic contexts.

- Fact-Mood, Imperative - Will-Mood, Subjunctive - Thought-Mood). Similar to

Latin, the same as in Russian.
Indicative represents an action as a fact: He is here.
Imperative expresses the speaker’s inducement (order, request, command, etc.) addressed to another person to do smth: Come here.
Subjunctive shows actions as non-facts (including not modal; + heterogeneous means of expression).

Subjunctive).
Indicative represents an actual action.
Subjunctive represents an imaginary action.

point is tense-retrospect shift:
The opposition of perfect and non-perfect phases

turns into the opposition of relative substitutes for the absolute past and present tenses of the indicative.
E.g., I know it (present real) - I wish I knew it (present unreal); I knew it (past real) - I wish I had known it (past unreal).
! Though this shift is very important in expressing unreality, tense and phase are verbal categories other than mood and should be treated as such. One category cannot be expressed by another. They are only means of expressing modality.

purely formal. The construction should/would + infinitive is a free

word combination.
The category of mood has died out. It has failed to maintain and strengthen its categorial status.
There is no correlation between the plane of expression and the plane of content.
I wish he came. I wish he would come. (same meaning, different forms)
I suggest that he would go there. He would go there if he could. (different meanings, same form)
,,The way to cut the ”Gordian knot” of problems posed by the analysis of modal meanings in the verb.’’ ~B.A. Ilyish