Are you aware how frequently we use "Do you want something to eat?", rather than "Did you want something to eat?"?
Actually, , Shun?
Results 1 - 10 of about 4,560 English pages for "Did you want something to eat?".
Results 1 - 10 of about 952 English pages for "Do you want something to eat?".
But actually, frequency has nothing at all to do with the fact that we DO USE the past tense FORM to be more deferential.
So, according to your reasoning, may I presume, using Simple Present "Do you want something to eat?" will be less polite? Then why do we usually want to be impolite?
"less polite" and "impolite" are completely different things, Shun. Just as in Japanese, casual speech does not always require the more formal 'masu' ending.
Both 'may' and 'could' are more polite than 'can' for permission yet 'can' is used more in speech than both of them; "may is especially rare in the sense of permission". [LGSWE - pg 493]
When we use less polite collocations, no one thinks that they are impolite. That is just nonsensical.
Here's another example.
"I was wondering if you could just drop me off over there."
The 'wondering' is not a finished event; 'was', a past tense FORM is used to make a more deferential request, a more polite request. It has nothing at all to do with time.
And another; we use a backshift to past tense FORM to mark reported or indirect speech.
A: I want to go for sushi.
B: What did he say?
C: He said that he wantED to go for sushi.
Here again the past tense FORM 'wanted' has nothing to do with tense/time. "wanting to go for sushi" is a yet to be, future event. But again, we make use of a past tense FORM to mark this for something other than past tense.
Look at the Time:
Will you ask the so-called 'softer' question that violates the time: "Did you eat something?", instead of "Did you want something to eat?"
Can't you see the time implications of the two statements are different? It is about Time, rather than Politeness.
I don't have the faintest idea what you're trying to say here, Shun.
By the way, it seems that you have missed the following point of using Past Perfect. Allow me to recap the time flow:
Please start a new posting for this issue.