Questions asked using past tense forms of Will/Can/Shall/Do, some examples like:
"Would you mind...?"
"Could you please...?"
"Should I do...?"
"Did you want any help?"
"Did you want something?"
It seems people are using past tense forms in these sort of questions, when there is nothing wrong to use present tense for the exact same meaning.
Why is that?
Is this a hint of being polite or humble? Is there a grammar rule for this construct?
I know people wanted to refer me to modals but Do/Did is not one of them. And even if you are thinking about modals, and we know their usages, still the question is why the past tense forms are more polite compare to present tense forms? Whats the reason behind English where past tense forms mean politeness?