"Dive" = "fly into"?


The words `飛ぶ` and `跳ぶ` are both read as `とぶ`, the former meaning "to fly" and
the latter meaning "to jump" (generally; don't know if they are
interchangeable at all).

The compound-verb suffix `〜込【こ】む` means that the action "goes in (to)",
"enters", etc.

So the word `とびこむ` means "to jump/dive into", both literally and figuratively
("jump into (doing) a mountain of homework", "butt in to someone's business",
etc.).

However, `とびこむ` is written with the "to fly" version of the kanji: `飛び込む`.

Why is this? When `跳ぶ` means jump and `〜込む` means "into", why wasn't **`跳`**
chosen for `とびこむ`? This doesn't make sense to me at all.




`飛ぶ` is the general term that covers all the uses of homophonous kanjis such
as `跳ぶ` and `翔ぶ`. `跳ぶ` is a specific one, entailing some mid-air movement
(such as pedaling your legs, etc.). As usual with homophonous kanjis, the
specific one can be replaced by the general one, but not the other way around.
In the literal sense "to dive in to e.g. a swimming pool", you can use `飛び込む`
as well as `跳び込む`. For the metaphoric sense "jump into homework/business",
`跳ぶ` is probably too specific because those senses do not accompany movement
in the air, and you have to use the general `飛ぶ`.




`飛ぶ` is the general term that covers all the uses of homophonous kanjis such
as `跳ぶ` and `翔ぶ`. `跳ぶ` is a specific one, entailing some mid-air movement
(such as pedaling your legs, etc.). As usual with homophonous kanjis, the
specific one can be replaced by the general one, but not the other way around.
In the literal sense "to dive in to e.g. a swimming pool", you can use `飛び込む`
as well as `跳び込む`. For the metaphoric sense "jump into homework/business",
`跳ぶ` is probably too specific because those senses do not accompany movement
in the air, and you have to use the general `飛ぶ`.

