The term " a lot" can be used as a noun to signify that you are talking about having a great deal of something, as in " I have a lot of cookies" . " A lot" can also be used as an adverb when you want to say that you do a great deal of something, as in " I make a lot of cookies" . The term is commonly misspelled as " alot" which doesn't mean anything. Some will misspell it as " allot" which
. is another word altogether. Perhaps you will find it helpful to review this grammar lesson at http://www.grammar-monster.com/easily_confused/alot_a_lot_allot.htm so that you will not make the same mistakes a lot.