Angelos

As I understand even in modern Mandarin the sound we write as <h> in Chinese is [x] and not [h], not to mention that most on'yomi were borrowed from Middle Chinese and not any modern Sinitic language

@vdegenne And the literal second result is 「変えれないと変えられない、ではどちらが正しいですか」, showing that even if it's non-standard, it's used often enough for people to get confused, not to mention that in the summary under the link it says 『「変えれないよ〜」と言うひともたくさんいますが、 よく言われている「ら抜き言葉」ですね。』. Considering you called someone else a loser on a comment under another answer, I'm starting to think you're a troll.

@vdegenne You can't seem to accept that you're wrong even when provided with evidence to the contrary, but here.

どうやら「ら抜き言葉」に直接関係する質問はないようですが、この回答で十分なはずです。

In my opinion, 'they' is the only acceptable choice, even in the most formal of writing. 'He' is stuffy and outdated, and 's/he' and 'he or she' are eyesores.

The Japanese phrase for 'smoke a cigarette' is たばこを吸う｛すう｝, or literally 'suck a cigarette'. There is nothing inherently 'smoky' about 吸う. You can use that verb just as well for vape sticks as for cigarettes.

Let us continue this discussion in chat.

@Lambie Letters are not sounds. Letters are not voiced or unvoiced. Sounds are voiced. The sound in kids is voiced /z/ There is nothing inherently voiceless about the letter S itself, nor is Z an inherently voiced letter - for example, in Spanish, it represents a voiceless /θ/ sound, and in many English words the letter S represents a voiced /z/ sound as in wise, guise, and of course kids.

@Lambie Or, okay, let me put it this way. Say 'bus' with your hand on your throat, really elongating the /s/ sound. Then say 'buzz' with your hand on your throat again, really elongating the /z/ sound. When pronouncing /z/ you'll find vibration in your throat, and /s/, no vibration. Try the experiment again with 'kits' and 'kids'. If you still say the /z/ in 'kids' is voiceless after that, then I'm afraid you're the one who doesn't know what voiced and voiceless mean. What do you think they mean, anyway? Also, looked up 'voiced alveolar sibilant'.

@Lambie Are you letting the spelling mislead you? Yes, we write S, but the sound is voiced /z/ by assimilation to the /d/. As a rule, plural or possessive S is voiceless after a voiceless non-sibilant consonant, voiced after a voiced non-sibilant consonant, and it becomes voiced /ɪz/ after sibilants.

@KentaroTomono Although I'm not a native speaker myself, every native speaker I've talked to has claimed that ある is more common; this matches my experience, too. You're the only exception.

@KentaroTomono I thought you were a native Japanese speaker. ある is far more common than either of the Kanji spellings, not to mention that here (I think) it's a subsidiary verb, so by official guidelines it shouldn't be written in Kanji anyway.

召し上がる is already 尊敬語. お召し上がりになる and the like are frowned upon and redundant.