A declarative sentence is basically a statement. This is by
far the most commonly used sentence type. In a declarative sentence, the writer
is making a statement (or declaration) about something or someone. Declarative
sentences end with a period. For example:
This computer is very old.
The stealthy submarine slipped past
the enemy’s defenses.
She sells seashells by the sea
shore.
All of these examples are declarative sentences because they
are statements about something or someone.