I thought this had been asked before (possibly by me), but I couldn't find it. I'm wondering why for certain verbs/words, instead of just a
自他 pair, there is a triplet (or possibly more) where two of the verbs are one type (
他) and the third is the other type. Some examples:
- 他 → 縮【ちぢ】める ： 自 → 縮【ちぢ】まる ： 縮【ちぢ】む → both?
- see @snailboat comment below - dictionary confirms. Exs.
- 自 → 寿命が縮む ： 他 → 「ちぢめるの文語形」in dictionary def.
- 他 → 繋【つな】ぐ ・ 繋【つな】げる ： 自 → 繋【つな】がる
- 他 → 緩【ゆる】める ： 自 → 緩【ゆる】まる ： 緩【ゆる】む → both? (same as above)
- 他 → 滅【ほろ】ぶ ・ 滅【ほろ】びる ： 自 → 滅【ほろ】ぼす
- 他 → 含【ふく】む ・ 含【ふく】める ： 自 → 含【ふく】まる
What's the deal with these triplets? Why are there two accepted verbs of one form for the same meaning? Are they somehow different? Is one of the two a classic/obsolete form like I talked about here? Does one of the two somehow rise to dominance over the other? I admit that I encounter
繋【つな】ぐ a lot less than
縮【ちぢ】む seems just as frequent as
縮【ちぢ】まる to me.
Any other examples would be great to list too.