I worked in California for a while and something that kept throwing people off was that I pronounce my "t"s in the English way rather than drop them to "d"s. So it's buTTer and not 'budder', thirTy not 'thirdy', etc. Once I started dropping them to "d"s too, things improved significantly, and I can see why a lot of British YouTubers and geeks develop this 'trans-Atlantic' affectation.

Another funny one I ran into a few times was how for a time like 8:30, we'd say "half eight" in the UK, but when I would casually say this in the US people would be like "half eight? you mean four?" It had never occurred to me this common British parlance would be unintelligible elsewhere. Of course, there are just as many things the other way around, although watching a lot of US TV will take care of that.

Oh wow, it actually is 8:30 in English. How interesting!

In dutch, half eight is 7:30 too.

7:40 is weird: "ten over half eight"

A little more formal would be "half past eight" which clears up the ambiguity, as does "quarter til eight". Not sure who uses that aside from occasionally in US.

Spanish does the same thing with time, so it's not uncommon.

That said, the way the French count numbers is, I think, universally confusing. Knowing the French, this is intentional :P

Half eight in Swedish is 7:30 :-)

Same in Russian. I think it expands to "halfway to the eighth hour" and since 12:00-1:00 is the first hour, 7:00-8:00 is the eighth hour.

I think it's the same in German too. Halb sieben is 6:30.

I’m from California and I had an Irish colleague there who, despite otherwise being amazingly well integrated, stuck to a hard “t” for certain cases of “th.”

So for instance if I might say “These three things,” he would say “these tree things.”

He was clearly able to make the sounds but in some cases he couldn’t. I never felt comfortable asking about it because I thought it might be a class thing.

The 'th' in Irish is usually dropped to 't' if a consonant is followed or at the the tend of a word. Death become Deat, Teeth become Teet, Thrice becomes Trice, Other stays as Other because a vowel is the next sound.

I also had that problem with the "ew" sound. I'm never understood if I ask for a "Mountain Dew" - I have to translate to "Mountain Doo" even when the context of a drink is clear.

The other one is asking for a cheese sandwich - that seems to throw Americans every time.

My favorite British-ism is, e.g., Monday week. A great simple way of referring to a week from Monday.

Monday week? We would say "a week Monday". Didn't realise this was a British thing! Though I'm Welsh, so perhaps my variation is a Welsh thing.