The two phrases are so similar that the average english speaker would most likely not notice if you use them incorrectly. However this is how it works: “lot” becomes the subject of the sentence “lot’s of” is a plural(p) lot “a lot of” is a singular(s) lot therefore our “to be” verb must match the quantity for “lot” Examples: 1.) There are(p.) lots(p.) of dogs or 2.) There’s(s.) a lot(s.) of dogs (There is —> There’s) Without markings: 1.)There are lots of dogs 2.)There’s a lot of dogs When speaking english, if you were to always use “There’s” nobody would ever notice this is wrong when combined with the plural lots. Only when speaking though, it would be wrong to type “There’s lots of dogs” on an important paper or such. There is one other case for this: If the mentioned noun is countable or not In this case we will use “milk” which is usually uncountable (milk can be countable if you have multiple different *types of milks*) When using an uncountable milk it works as such: 1.)“There’s(s.) a lot(s.) of milk(s.)” or 2.)“There’s(s.) lots(p.) of milk(s.)” Without markings: 1.)There’s a lot of milk 2.)There’s lots of milk So, as you can see, our “to be” verb remains singular because our milk is uncountable Overall, when SPEAKING english, if you always use “There’s”, your sentence will ALWAYS sound correct and you can use either “lots of” and “a lot of” as you wish. But when writing formally, that is how it works to my knowledge Sorry this explanation is so long, it’s such a small difference it’s difficult to explain in short! Hope this helps!

no difference

Lots of.Add a complex number, A lot of.You can add the plural or the singular.

The usage is different.Lots of I often use in In an occasion called spoken language ，Can only modify countable nouns . a lot of is used in written terms and often appears in formal situations Can modify countable and uncountable nouns .

Here are some lots of ideas that come to mind: 'Lots of students are lazy freeloaders a lot of the time.' (uses both forms you need clarity on) That should be the end of it , really... but: 'A lot of students post questions to which they already know the answer.' (Generation Crazy, I know) 'Lots of students can't be bothered working it out for themselves, thesedays.' (Generation Gimme) 'Lots of students think asking a difficult question has merit, where it does not'. (Gen. Lost the plot) 'A lot of teachers think this will be a shorter response than it turns out to be.' (Gen. Xtremely Narky) ''A lot of students post a single line question knowing full well it will require a chapter and verse of an answer that they can find online anyway.' (Generation Spiteful) 'Lots of teachers say they are but they are not.' (Gen. fake it till U make it) 'A lot of students ask questions way above their ability level, but because they don't use teachers, other than as peripheral, arbitrary ego massuers, they never realise they are on the slow loop track to language stagnation. (Gen. Denial) Not a lot of teachers use irony, humour and mischeivious responses to generate thinking in students. There is not a lot of evidence that it's worth the effort. (Gen. Fool) Hope that helps.