it's kind of weird how many languages have multiple writing systems that are mixed together in writing

all european languages inherited the idea of upper and lower case from a complicated series of interactions and now have mostly agreed on rules for what gets capitalized except German, which disagrees

though I think it was in cyrillic from the beginning, unlike the roman and greek alphabets where it, i think independently appeared twice? i don't know

and then japanese has That Whole Mess with borrowed chinese writing used for nouns and then all the Grammar is written in hiragana except when it's in katakana instead for reasons

the arabic abjad has rules about how the characters connect to others that just comes of it being a cursive script, but the forms can sometimes be extremely different from one another

but on the other hand the majority of writing systems that were not based on the roman alphabet have just a single writing system. all the brahmic scripts are used alone, not intermixed with others, and people are not generally required to know more than one in order to communicate competently in that one. as far as we're aware the canadian aboriginal syllabic writing system also only has the one form for each character, and the same goes for the Cherokee syllabary. The Han languages (Mandarin, Cantonese, and relatives) have both traditional and simplified logographs but they are not (I think?) intermixed in the same inscription. Korean just has the single set of hangul, though they historically used the same hanzi borrowed from the Han languages, which might still be used for some traditional things, I don't know