Where does “невмоготу” come from?

невмоготу (Russian) comes from Russian в, from Old East Slavic въ, from Proto-Slavic vъ(n), from Proto-Indo-European h₁n̥, from Proto-Indo-European h₁én — in.

Ancestry of “невмоготу”, step by step

невмоготу traces back through 3 separate lines of ancestry.

via Russian в

Step	Language	Word	Meaning
1	Russian	в	in, at, on; to, into; at, in, on
2	Old East Slavic	въ	inside
3	Proto-Slavic	vъ(n)	in, inside, within; in, into, inside; at
4	Proto-Indo-European	h₁n̥	—
5	Proto-Indo-European	h₁én	in

via Russian не

Step	Language	Word	Meaning
1	Russian	не	not, no, -n't, without; Idiomatic negative usage;...
2	Proto-Slavic	ne	not
3	Proto-Balto-Slavic	nē	not
4	Proto-Indo-European	né	not; no

via Russian мочь

Step	Language	Word	Meaning
1	Russian	мочь	can, be able to; may; power, might
2	Proto-Slavic	moťi	to be able
3	Proto-Indo-European	meǵʰ-	to be able

Every word from Proto-Indo-European h₁én →Every word from Proto-Indo-European h₁n̥ →Every word from Proto-Slavic vъ(n) →