On some occasions, a writer may decide to use a semicolon to conjoin two sentences together, instead of forming a new sentence. The reason being is that the two sentences are closely linked, for instance 'The sky seems cloudy; indicating a high possibility of precipitation'.
you are an idiot
There are no sentences for this. Those are not words.
Some people are pessimistic; they see the glass as half empty.
some people are agents
There is no such word.
A semicolon is used to represent a long pause in the middle of a sentence. The pause is longer than that of a comma but smaller than the pause represented by a colon, hence the 'semi'. It is mostly used between clauses that could be separate sentences but have some logical connection.
I am addicted to bacon.
Here are some sentences using the phrase "out of": Before we install the refrigerator, we are going to have to get it out of that box. Please stop trying to get out of doing your homework.
Cats go meow.