Is it at all correct to say let me by or let me past? If so, is it a common expression or an old-fashioned or rare one? I guess most people would say make way to indicate (maybe a bit rudely) that they want to go past someone who blocks the way. Am I right? Is could you please let me past a good and acceptable way of saying this more politely?
Make way sounds archaic, I wouldn't expect it in ordinary speech, only in historical/pseudohistorical contexts or in regard to royalty (in case it matters, I speak American English). The rest of these are pretty much synonymous, if differing in politeness. These are pretty polite:
- Excuse me, could (or can) I get by you?
- Could you please let me pass (or past)?
- Excuse me
- Could (or can) I get by you?
While there are somewhat rude, especially without a please at the end:
- Let me by
- Let me pass (or past)
I use excuse me most often out of these, when passing by a person or through a crowd of people, sometimes coupled with a sorry for inconveniencing them (however slightly).
You could add please to the end of any of these to raise the politeness a bit. Adding a thanks after someone moves for you would be appropriate, too. Excuse me can mean many things, but in this context, it's usually clear.
Here are a couple of acceptable ways to ask the question:
May I pass, please?
May I get by, please?
Can /Could I get by, please?
Will/Would you let me by, please?
Or you can simply say "Excuse me,[please]" and touch the person lightly on the shoulder/arm. It's usually obvious that you want to pass and you are asking them to clear the path for you or something.