Is there a tin-opener in the house? / ...there was no bus

[jesus]

Hello.


a) Is there a tin-opener/Are there any tin-openers in the house?

What is the difference or little difference in meaning?

b) We had to walk home because there was no bus /there were no buses /there weren't any buses / there wasn't a bus.

What is the difference or little difference in meaning?

Thanks.

[spacechem]

No difference in meaning.

I will point out that, if you were to ask an American for a "tin opener", she would not immediately know what that is. We use the term "can opener", and generally replace the more British "tin" with "can" to refer to the same thing.

"Can", in this usage, refers to not only the receptacle, but also the process. My mother used to preserve summer fruits and vegetables by processing them and putting them in jars for storage. She called it "canning", mostly because the process is very similar to that used to put foodstuffs into cylindrical metal containers for indefinite storage.

[Pete]

Hello.


a) Is there a tin-opener/Are there any tin-openers in the house?

What is the difference or little difference in meaning?

b) We had to walk home because there was no bus /there were no buses /there weren't any buses / there wasn't a bus.

What is the difference or little difference in meaning?

Thanks.
I'd say that in both cases, when you generally would expect for there to be more than one of the thing in question, you use the plural in a question or a negative sentence. You use the singular when you generally would expect there to be one of the item, or else to provide special emphasis, giving an idea like "there is not even one" or "is there even one?"