maybe i'm reading into it too much, but isn't it interesting that the word for tea in korean in 차 (cha), which is similar to the tamil word for chai (spiced tea with milk), சாய் (cay)? tamil and korean share a lot of other similar words, like 아빠 (appa) and அப்பா (appa) for father. it's kind of cool.
Most languages use either some form of the word "tea/tee/thé" or "cha/chai/shay" for tea. It comes from the Chinese word for tea 茶 which is pronounced "cha". That's why Koreans call it 차 and Japanese お茶 ("ocha"). The word cha spread all over the world, in Arabic it is شاي "shay" and in Swahili it is "chai". In Taiwan they also used the word 茶 but pronounced it "te" and when the Dutch traders brought tea back to Europe, that's how it came to be called "thee/thé/tea", etc. So you were not overthinking, there is a reason why the words sound so similar all over the world! :)
There’s an interesting theory that 한글 is distantly related to the Indic writing systems and ultimately Egyptian hieroglyphs or maybe even ancient Sumerians Cuneiform from 3200 BC:
- Egyptian hieroglyphs possibly influenced by Cuneiform?
- Proto-Canaanite script descended from Egyptian hieroglyphs
- Phoenician script descended from the Proto-Canaanite script
- Aramaic script descended from the Phoenician script
- Brahmi script (the earliest Indic script) descended from the Aramaic script
- Gupta script descended from the early Brahmi script
- Nagari script started in ancient India as variant of the Gupta script
- Tibetan script is created by Thonmi Sambhota based on the Nagari script
- ʼPhags-pa script is designed by a Tibetan monk (and so descends from the Tibetan script)
- King Sejong introduced 한글, inspired by Mongol ʼPhags-pa script
Bullet point #10 is quite a stretch and runs counter to the popular narrative, but professor Gari Ledyard of Columbia University thinks there is at least a limited connection. Whether any of this is true or not, 한글 is quite a masterpiece made with a lot of original creativity.
English doesn't use the indefinite article (a/an) for uncountable nouns, and tea is uncountable most of the time. Thus, with almost any context or with no context at all, "a hot tea" would sound wrong to native English ears (at least in American English).
However, almost anything can become countable (at least in informal speech) as a menu item, so one may say "a hot tea" or "three hot teas, an iced tea, and a water" when placing an order. In almost any other context (that I can think of), however, you would be required to use a countable noun in order to use a/an--you could say, "a cup of hot tea" for example (because cup is countable).