Why couldn't one combine rules from languages for sentences with the same intended meaning?

Question

Why couldn't one combine rules from languages for sentences with the same intended meaning?

So that I could, for example, write Finnish with the same comma rules as in English?

Rather, one must subscribe to the rules of a particular language.

Answer 1

You can if you want; nothing is stopping you.

But if you're writing in Finnish, it's presumably because you want Finnish-speaking people to understand you, and Finnish-speaking people are used to the rules of Finnish, not English. So if you want to be best understood, you should stick to the rules and customs of Finnish.

Σιμιλαρλυ Ι κουλδ ωριτε θις ανσωερ βυ (αβ)υσινγ θε Γρεεκ αλφαβετ, βυτ θατ ις νοτ εσπεσιαλλυ υσεφυλ ιφ Ι ωαντ Ενγλιση-σπεακερς το υνδερστανδ με. ("Similarly I could write this answer by (ab)using the Greek alphabet, but that is not especially useful if I want English-speakers to understand me.")

Or, I the rules syntactic of language another in English use could, because I the verb at the end of the sentence put like might. This to speakers of English similarly be difficult would. ("Or, I could use the syntactic rules of another language in English, because I might like to put the verb at the end of the sentence. This would similarly be difficult to speakers of English.")

The purpose of language is generally to convey information and be understood, and the "rules" of language aren't defining what you're allowed to do, so much as what you should do if you want people to understand you as much as possible.

Answer 2

Why can't Australians drive on the right side of the road, and Americans drive on the left? Why can't soccer players pick up the ball? Why can't orchestral musicians choose which key they want to play?

Just like all of these, language is cooperative. Sometimes a choice may be largely arbitrary, but it still matters that everyone cooperate and follow the same rules. There are varying levels of importance to these rules and conventions; punctuation is of low relative importance, as is spelling. Anyone on the internet (or who knows children) will have experience with reading misspelled or poorly punctuated text. Grammar and vocabulary is much more important for effective communication. If you use lots of words from another language then only those familiar with both will be able to understand. If you don't follow the grammatical standards of a language, then people either won't understand, or probably worse, they'll misunderstand, as they try to make sense of what you've said or written. English for example has a fairly strict word order. Swapping the order of the subject and object won't always appear ungrammatical, instead it can be grammatical, but just communicate the opposite meaning of what you intended.

Answer 3

We can - it's all just a tradition... In fact, most of "western" world uses the same punctuation and capitalization rules (minus some minor differences). Note how in both English and Finnish you start the sentences with a capital letter, end them with a dot (or a question or an exclamation mark); words are divided by spaces (but not in front of commas), quotation marks work in the same way (though a bit different visually), typography is more or less identical. Even Greek and Cyrillic based languages follow almost the same rules (minor details like a different question mark aside). OTOH, Arabic and CJK languages have very different rules (but still, they imported quite a lot of European "rules").