Yeah, that's a fair clarification. You meant "natural" as in the opposite of "wooden", not "natural" like "it sounds like ordinary real people talking."
One of tricky things for people whose introduction to comics was manga tends to be writing dialogue that reads like it was translated from Japanese. It's just this funny thing, where manga has a very specific sort of flow to the dialogue, due to having been translated, and there's always this decision to make on how much to treat that as a stylistic feature of manga that a manga-style comic feels somehow weird without, and how much to decide to keep only the manga visual aesthetic, but in all other respects to write the comic like you're writing an English Language thing.
Some people might say, "well, obviously, you should write in just plain English! Don't be a weeb!", but it's then worth considering that comics of other styles do also come with certain stylistic conventions to the dialogue that feel natural if you read a lot of them, and will even feel "missing" if they're absent, but come across silly and unnatural if you're not into that type of comics.
When I was in my early twenties, doing one of my first bits of paid comics work for a UK hardware store, on a piece of work designed to help sell the shareholders on a new digital ordering system, I was given this very straightforward script that simply described what the man in the story was doing in each panel. He went to the website, he ordered his stuff, he got his notification, and then he went and picked it up. I drew the panels and lettered it all, got paid, all good.
...But then later, the client came back to show me the version he'd "improved" with "better" writing that "felt more like a proper comic", and this is where this phenomenon struck me. The man in question was about the age of my parents, maybe just a little younger. So what was his idea of what "comic dialogue" should sound like.
"By jove! This is a spot of bother! It seems the queues at the local [hardware shop] are endless!"
"But this doesn't bother our man!"
"He whips out his trusty mobile phone..."
"And sorts it right out in a jiffy!"
...Because this man grew up reading old British "for boys" comics in the 1960s and 70s, and that's what the narration was like. To him, a comic with a perfectly instructional, neutral, modern writing style didn't feel like a comic.
And the same phenomenon affects all of us, reading and making comics. Korean webtoons also have a very distinctive writing style, Canadian and American indie comics definitely have one (if you read Scott Pilgrim, Lumberjanes and The Girl From The Sea, you'll notice it), and you can often spot a Homestuck just by how they write. It means we all kind of have to decide, "okay... how comicky do I want to be? Or do I want to be more naturalistic? Or do I want to draw in the style of this sort of comic, but write in the style of this sort of comic?
In a way, the style of the writing is just as much of a choice as the style of the drawing! 