Please let me know if you have any questions

Roses are red violets are blue jokes
Your driver license may be suspended for causing
How long does it take to get an oil change?

Which one is correct and incorrect? There are 2 type: “please let me know if you have any question” or ”please let me know if you have any questions”

So, what is “any” means?. In this sentence, ‘any’ is functioning as an adjective. It is not a pronoun. And it is neither singular nor plural.

‘Any’ has the definition as an adjective. It means such as “One of, each of, or a started amount of (something that is more than one or has a number of parts). It is not saying which particular part is meant.”  It requires a plural noun.

Please let me know if you have any questions

“Please let me know if you have any questions.”

“Please let me know if you have a question or problem with …”

“Please let me know if you question any of my facts.

As everyone has highlighted, we can answer that “any question” and “any questions” are both correct. Although they differ subtly, “any question” means “one question” but the other means “one or more questions”.

Please let me know if you have any questions 2

Exactly, this is the sort of question when drives grammar nerds wild. Because of context is so important. Especially, in most grammar discussions, “any” is involved.

We can expand a bit on this. The basic rule is that you should say “any questions if you are allowing more than one question per person. However, if there are high chances that all of them have multiple inquiries (f.i.:”Does this product work under water? And when every possible question is ultimately complex, i.e. If so, you are in the clear using “any question” with the question: what is the max depth? Does it stand sea water?”_). Because there is a fundamental understanding that each is really multiple in that case.

Besides, there is another way to get out of this cleanly. We could write: “Please let me know if you have any question(s)”. However, this only works in writing.