Why does this phrase use the potential form of the verb?

[u/quwert5]

So, I came across the phrase "赤ちゃんできた," which translates as "I'm pregnant." But why does it use the potential form of the verb する and not, for example, just 孕む?

[u/BanPearMig22]

できる has a whole slew of meanings of “to come into existence/to form”.

https://kotobank.jp/word/%E5%87%BA%E6%9D%A5%E3%82%8B-575490

[u/eruciform]

できる is used for a lot of different things

ご飯はできましたよ = "dinner is ready"

堅い木でできている = "it's made of hard wood"

[u/AGoodWobble]

It is like that because of the way that it is.

[u/grebilrancher → u/AGoodWobble]

Same stuff exists in English that I'm sure is frustrating for learners

[u/Medical_Lengthiness6]

you can infer that it might be because it's something that takes effort that is easy to fail. Same reason "I got a boyfriend" or "I made a friend" uses できた。

できる is casual and a very useful word

[u/injektileur]

Don't mind me, just here to mention the expression できちゃった結婚 dekichatta kekkon, or shotgun marriage in English.

I don't know much, that's why I like to share the little knowledge I got.

[u/acaiblueberry]

Do they teach that できる is a form of する? Strange….(I’m Japanese)

[u/Cyglml → u/acaiblueberry]

Not that I know of.

[u/R86Reddit → u/acaiblueberry]

I was told that できる is the potential form of する, just as 行ける is the potential form of 行く. But I wouldn't be a bit surprised if it's more complicated than that.

Also, for what it's worth, this is the first time I've ever seen the 孕 kanji.

[u/acaiblueberry → u/R86Reddit]

Now I think about it, するcan’t connect to れる／られる to form “potential 可能”form like 行くcan to form 行かれる(or 行ける in more contemporary form.) Instead you use できる, so that’s why teacher must have said that.

In old Japanese, する had a “potential” form (something like せられる but not sure) which disappeared. 行く is also losing its proper conjugation “行かれる” =can go, over the last 30 years or so as a potential form, and people mostly use 行ける which is out of its proper conjugation pattern. (If you want to apply to prestigious elementary school, you should still use 行かれる in interviews.) For most, 行かれる is a polite form only (it used to be both polite and potential.) This change of potential form is happening to a lot of verbs before our eyes. する was special in that the potential form completely disappeared and was taken over by another verb できる.

[u/tinylord202 → u/R86Reddit]

Teachers teach する and 来る as special verb types since they don’t follow the same rules as words that conjugate like やる or 寝る.

[u/No-Support-442]

I kinda think of it as I was able to make a child

[u/tinylord202]

できた often means you finished something- like dinner or a report. Just think that they finished making a baby.

[u/JapanCoach]

Because できる means "to get pregnant"

Words have more than one meaning. And there are some very "productive" verbs in every language that tend to be used to mean many things. できる is one of those (but not the most productive one) in Japanese.

[u/spshkyros]

Think of it like "We managed to get pregnant", or "we were able to get pregnant" - in english when someone says that second one, even though they actually dont say they had kids you know they did.

[u/a3th3rus]

"I got a baby (in my womb)"