Oxford dictionary defines declarative sentence as :
"A statement in the form of a declaration."
and Proposition as:
"A statement or assertion that expresses a judgement or opinion".
What is the difference between declaring something or passing a judgement or an opinion?
Because when you declare something to be 'true' or 'false' it is like passing a judgement or an opinion. So, does that mean: All declarative sentences are propositions and Vice Versa?
If so, then why we have separate words declarative and proposition.
My question is closely related to "logic", but I think, if I understand the basic difference between the words declarative and proposition, then I will have some good idea about technical grammar related to logic.
Best Answer
"declarative" is a grammatical property, while "proposition" refers to the content. "Do not smoke" is in the imperative mood, while "I don't want you to smoke" is written as a declarative sentence. While they are different grammatical moods, they have essentially the same content. "Who doesn't like ice cream?" is not explicitly a proposition, but implies a proposition ("Everyone likes ice cream.") while being an interrogatory, rather than declarative, sentence.
It's somewhat like the difference between "plural" and "many". "many" refers to the physical amount, while "plural" is a grammatical term that refers to how a noun is inflected. "proposition" refers to the abstract notion of a claim, while "declarative" refers to the form in which it is presented. The declarative mood is a grammatical form that is generally used to express propositions, just as adding an "s" to the end of a noun is a grammatical form that is generally used to express that there are more than one of something.