SAVOIR-FAIRE
I've learned French, but 'before' (that's avant)
Who'd have guessed to say 'having' — ayant?
Faire: its participe present,
Faisant is quite pleasant;
For savoir, though, it's (strangely) sachant.
Check that out with your local savant.
Dr G.H. and Giorgio Coniglio, 2022
Authors' Note: The present participle (participe présent) is used much less commonly in French compared to English. In contrast, infinitives are used more often, so 'knowing how to', or 'knowing and doing' is described by savoir-faire, whereas sachant-faisant seems à rire (laughable).
All the French verbs mentioned here, as well as avoir, to have, are irregular, so their roots undergo weird transformations in some circumstances. Savant, an archaic form derived from savoir, is still in use as a noun for 'someone who knows' (a prodigy).