From Can’t Make Fewer Mistakes? At Least Make Lesser Ones
Fewer versus LessSee also Fewer or Less?
Fewer (adjective) means of a smaller number. Use it when referring to something that can be counted in individual units.
Less (adjective) refers to a smaller amount of money or degree of something that is not counted in discrete units.
The fewer responsibilities you have, the less likely you are to succeed.
Less versus Lesser
Less (adverb of comparison) refers to a smaller extent, amount or degree.
Lesser (adjective) means smaller or less important.
John may be less intelligent than Bill, but he has great strength of character; all things considered, Bill is actually the lesser person.