> But once "thank you" is said, most people awkwardly respond with "ah", because there's no phrase in the language for "you're welcome".

This reminds me of my neighbour’s doormat (in Germany). As most doormats, it has a text on it - usually that’s something like "Willkommen" (Welcome) or somesuch. This particular doormat says "You’re welcome!", continuously irritating my English-native friend when walking past it.

>But once "thank you" is said, most people awkwardly respond with "ah", because there's no phrase in the language for "you're welcome".

In London I've noticed that instead of saying, "you're welcome" people prefer to say "no worries", which is far more casual. I don't know why that phrase started to be used but if I had to give a guess I'd say that it was out of awkwardness because there wasn't a less formal/personal response to use.

There are different degrees of gratitude you're expressing with a "thank you":

- Thanking for an ordinary action, i.e. after buying something at a shop: no answer.

- Thanking for something that didn't cost me very much, i.e. lending £20 to a friend: I usually answer with "no worries (mate)".

- Thanking for something that cost me in some way (time, money, effort), i.e. helping pushing a stranger's car on the street: "You're welcome".

I've heard Australians say "no worries" (often with a trailing "mate") a lot. I always thought it originated there.

As an Australian I can say that "no worries" is very common here (ocker). It has a bit of an ambiguous meaning as it implies that the person saying thank you didn't really need to, but at the same time it is a means of acknowledging that you recognise and appreciate the thank you.