Theoretical Grammar The subject-matter of theoretical grammar. Its relation to practical grammar

e.g. Marvelous! Horrible! How very interesting!
e.g. No birds singing at the dawn (Strong resemblance to 2 member sentences).
e.g. I saw him there. Yesterday (parselation).

According to the purpose of the utterance: declarative, interrogative, imperative, exclamatory, ? optative. Prof.Ilyish: before dividing sentences into 3 classes we should divide them into emotional and non-emotional and within emotional we can establish 4 classes.

The strictly declarative sentence immediately expresses a certain proposition, that is why the actual division of the declarative sentence presents itself in the most developed and complete form. The rheme of the declarative sentence makes up the center of some statement as such.
The strictly imperative sentence does not express any statement or fact, i.e. any proposition proper. It is only based on a proposition, without formulating it directly. Namely, the proposition underlying the imperative sentence is reversely contrasted against the content of the expressed inducement. It is so because an urge to do something (i.e. affirmative inducement) is based on a supposition that something is not done. An urge not to do something (i.e. negative inducement) is founded on the supposition that something is done or may be done. E.g Don’t talk about them (They talk about them). Thus, the rheme of the imperative sentence expresses the informative nucleus not of an explicit proposition, but of an inducement – a wanted or unwanted action.
The actual division of the strictly interrogative sentences is uniquely different from declarative and imperative sentences. It expresses an inquiry about information which the speaker does not possess. Therefore the rheme of the interrogative sentence, as the nucleus of the inquiry, is informationally open (gaping). Its function consists only in marking the rhematic position in the response sentence and programming the content of the rheme in accord with the nature of the inquiry. The thematic part of the answer is usually zeroed since it’s already expressed in the question: e.g. How are you? – Fine, thanks.