A Lot Of, Lots Of, (A) Plenty Of

In affirmative sentences, the use of a lot of, lots of, or plenty of are to talk about large amounts and quantities, particularly in conversation and informal writing. They are used with both countable and uncountable nouns.
Examples:

· Lots of her students went on to become teachers. (Countable noun)
· We had a plenty of hotels to choose from. (Countable noun)
· John offered me a lot of money for the car. (Uncountable noun)
The use of plenty of is used instead of a lot of or lots of. However, plenty of means ‘enough, or more than enough’ and is therefore not likely in certain contexts.
Compare:
· We took lots of food and drink on our walk through the hills. (or…. Plenty of…) and
· Jim does not look well. He is lost a lot of weight. (‘plenty of’ is unlikely here)
Do not use plenty without of before a following noun:
· We have got plenty of time left (not We have got plenty time left.)