penance (n.) [←] late 13c., "religious discipline or self-mortification as a token of repentance and as atonement for some sin," from Anglo-French penaunce, Old French peneance (12c.), from Latin
pænitentia(see penitence). Transferred sense is recorded from c. 1300.
penitence (n.) [←] c. 1200, from Old French penitence (11c.)
and directly from Latin
paenitentia"repentance," noun of condition
from paenitentum (nominative paenitens) "penitent,"
In modern English, 'penance' differs from 'penitence'.
However, modern French lacks a cognate of the English 'penance'.
Instead, 'penance' seems to be translated as « pénitence » (nf).
Per contra, per the bold above, Old French did contain a cognate of the English 'penance'.
So how did the same Latin etymon
paenitentia evolve into all this complexity?
Please expose and explain all hidden, missing semantic drifts and links.
I'm unversed in Latin, but I noticed that Etymonline above spells
paenitentia differently: first with the ash grapheme, then 'ae' separately. Please advise.