Grammar is mostly independent from writing systems. It usually is a phonetic representation of the language. Usually a single symbol has a certain translation into a vowel or consonant, sometimes it is a group with such a translation (e.g. th, sh, ou, etc.)

With English, this is a bit different, because the great vowel shift and some imported typesetters created a discrepancy between the spoken word and it’s pronunciation on the one side, and that word’s written representation.

Writing system has nothing to do with grammar, and languages are not “based on” writing systems. Languages are systems of sounds which encode meaning. Writing systems are met visual representations of those sounds

For example, Persian is written with the same alphabet as Arabic, but its grammar is more similar to that of Hindi, which is written with an entirely different system. Arabic, meanwhile, is more closely related to Hebrew, which has yet another writing system.

Languages can be written with multiple systems, such as Hindustani, Mongolian, Romanian, and K’iche. Languages have switched from one writing system to another, such as Persian, Turkish, and Scandinavian. Notably, Korean and Vietnamese both switched from Chinese characters to alphabets. Vietnamese uses the same writing system as French, but their grammars and sounds are very different.

When I was last seriously studying Japanese, I remember finding a YouTube video of a Japanese person teaching English. And I remember one point he made (I understood enough Japanese to follow a certain amount of what he said) was that the name of a given letter in the English alphabet was not the same as the sound it makes.

(In case anyone reading this doesn’t know, Japanese has a couple of phonetic alphabets. (Honestly, hiragana and katakana are probably more “phonetic” than English letters in a way.) But for those characters, there’s no distinction between the character’s name and the sound it makes. For instance, the sound the hiragana character “す” makes is similar to the English name “Sue”, and the name of that character is exactly the same. There’s no need for any distinction between the name of a hiragana/katakana character and the sound it makes in Japanese.)

It just wasn’t something that had occurred to me that some learners of English would have to be explicitly taught the distinction between the name of a letter and the sound it made, so it was interesting to hear.

I really need to get back into studying Japanese.

The way the question is framed is a tad confusing to me. The historical development of writing systems by humans is unambiguous, in that the spoken language came first and then writing systems later. So the idea that learning a spoken language is easier/harder due to its writing system is a strange mismatch of not-really dependent factors.

Insofar as Japanese, Mandarin, and Cantonese are concerned, my cursory understanding is that Japanese uses a different ordering for nouns and verbs, while the latter two have more similar ordering to English, Korean, Vietnamese, and western European language. Someone should fact check that.

That said, English is not a pinnacle example of a alphabetic language, because it has so many loanwords that its pronunciation system strains to logically capture all its rules. The romance languages do a more decent job of matching the written language to the spoken language.

At bottom, learning to speak a foreign language can be done without learning its writing system. When speakers can’t write the language, it is called illiteracy. But to learn a writing system without its spoken language, there are few examples, because every writing system conceived by humans always encoded some aspect of the spoken language’s grammar. Pre-1900 Vietnamese using the Chinese script is not fully comprehensible to a Japanese reader, as an example.

I’ve met plenty of Japanese who speak fantastic English. Everyone had to study it from Jr. High here and, starting a couple of years ago, starting in elementary school. Pronunciation is very hit or miss since many of the teachers in Japan can’t even hear the difference between l/r and the like sometimes and ALT (assistant language teachers, typically native speakers of English) are rarely allowed to drive things and push more from what I read.

Many Japanese who went to uni had to pass an English test section to do so from what I understand. You can look up sample questions on the web. As such, many can read English to a certain degree, but output and listening are often issues.

My wife hated English class and never paid much attention. She’s working her way through a textbook now and she finds various aspects difficult (looking at you do as in do you like potatoes – WTF is the do doing there? Why not like you potatoes?!) The alphabet portion, though, is not an issue in itself. Pronunciation requires a lot of work but I think that’s because English orthography sucks. However, if you grow up where a whole range of sounds just map to one in your language (l/r problem again), you don’t learn to differentiate between the various points in that range and can’t hear that difference without a lot of work. Definitely so for sounds that don’t exist at all. Many people going into Japanese have trouble differentiating germinate consonants and tsu vs su.

Did your identical post in asklemmy get taken down or did you delete it?

Japanese has kana though. So a single character might not be a word. So it’s quite different from Mandarin in that respect. That said Mandarin does have pinyin with both romanized and bopomofo versions that act as a reading guide so I don’t think the idea that a single character may not mean a word is that strange of a thing.