Concerned at the chaotic and confused presentations in grammar books and on websites, Geoff Pullum provides a clear account of clause type, plus a homework.

There are two kinds of interrogative sentences. The first type are affirmation questions wherein the speaker is trying to get the addressee to assert whether or not a proposition underlying the ...

There are four: a declarative sentence makes a statement, an interrogative seeks an answer, an exclamatory expresses surprise and an imperative gives a command.