In grammar, the kind of sentence that makes a statement or “declares” something: “He eats yogurt.”
The topic must be given some definite expression in a declarative sentence before any real argument is possible.
The period, or full stop, marks the end of a declarative sentence.
Each reason given in support of the issues and each subreason should be no more than a simple, complete, declarative sentence.
A declarative sentence declares or asserts something as a fact.
We call the first sentence a declarative sentence because it makes a declaration.