Note the definition:
Operators are the modals (
can, could, will, would, etc.) and forms of
be -- and also forms of
do or
have used as auxiliaries.
The negative adverb
not can only be carried by an operator,
i.e., can only be used when accompanied by an operator. To negate a
sentence without an operator, the operator
do must be added together with
not. The technical term for the addition of a form of
do is
do-support.
Operators underlined below. Note the third example, where negation requires
do-support because the affirmative sentence has no operator.
Popcorn can be eaten. > Popcorn cannot be eaten.
Popcorn is eaten. > Popcorn is not eaten.
People eat popcorn. > People do not (don't) eat popcorn.
CJ