There appears to be a strong correlation between the standard Japanese verbs 助ける tasukeru, 助かる tasukaru, 助く tasuku and 救う sukuu, as well as the Kyushu shimo nidan verb すくる sukuru. In standard Japanese, 救う implies more strongly the idea of rescuing from a danger or a crisis than 助ける. In Southern Kyushu, すくる is used in much the same way as standard Japanese uses 助ける.

The question here is, given the parallel between sukuru (*sukeru) and tasukeru (*tasukuru), and noting the verb sukuu:

• What does the prefix ta- do? Are there similar verbs for comparison?
• What difference exists between sukuu and sukuru?

Side note: the verb 透ける sukeru exists in Japanese, but means "see-through" or "transparent", and is connected to the verb 透く suku "to be transparent", and not the above verbs.

Suggestions of possible relations:

• 戯ける tawakeru "to joke around" ? 湧く waku "to feel emotions arise"
• 手向ける tamukeru "to offer (something) to a god or deity" ? 向ける mukeru "to turn towards (something)" ? 向く muku "to face"

Given this last example, could the prefix in 助ける tasukeru have originated from the word 手 ta, thus implying "helping with hands"? Or is it possible that it's an intensive prefix, as suggested by Otto Harrassowitz Verlag on page 125 and also on page 124 for the relation between tabashiru and hashiru, in the book "Is Japanese Related to Korean, Tungusic, Mongolic and Turkic? "? If so, what difference exists between sukuu and sukuru (*sukeru)?

Also, if the form of the verb sukuru/sukeru implies derivation from the nominal i-form of a previous verb *suku combined with the old auxiliary verb 得る uru/eru, does this verb suku still exist? Could it be related to 鋤く suku, meaning "to plough"?