A formal sentence should include subject, verb and sometimes object.
Any sentence that is short for an element of those is called incomplete sentence.
Who was the 35th president?
Noun or pronoun.
I have a special pet in the entire world.Guess what it is?
Writing an answer to this question is "inconvenient" for me.
We need the police to enforce law and order
I will now taunt you by not answering this question properly.
His devotion to his training set an example for the other students.
Convection causes it to rise, causing a valley breeze
Wrong. You must say, "the scissors are on the table"
Example( you made a blunder when you forgot to spell sentence with a c after the n)
a sectional sofa is a good sofa for small homes
"programs" is a noun in that sentence.