What is the Difference Between A Lot and Lots Of?

The difference between "a lot" and "lots of" lies in their formality and usage. Both phrases mean "a large number or amount" and can be used with both countable and uncountable nouns. However, there are some distinctions:

Formality: "A lot of" is considered more formal than "lots of". "Lots of" is more informal and is commonly used in spoken English.
Negative sentences: In negative sentences, "a lot of" is sometimes used instead of "much" and "many". For example, "There weren't a lot of choices".
Questions: In questions, both "a lot of" and "lots of" can be used when expecting a large quantity of something. For example, "Are there a lot of good players at your tennis club?" or "Are there lots of good players at your tennis club?".
Using 'a lot' as an adverb: "A lot" can also be used as an adverb, meaning "very often" or "very much". It is often placed at the end of a sentence and never before a noun. For example, "I like basketball a lot".

In summary, both "a lot of" and "lots of" can be used to express a large amount or number of people or things. However, "a lot of" is more formal and can be used in negative sentences and questions, while "lots of" is more informal and commonly used in spoken English.