s'acharner a faire

[alan gould]

it means "to try desperate to do" or "to persist in doing."  i just came across it.  sounds like it's worth adding to my vocabulary.  is this a common way to say that u persist at doing something?  Tx

[alan gould]

i meant to say "desperately"

[George Hunt]

I don't think you have to use the "desperate" connotation (it could involve desperation)

Maybe "strong  or fierce resolve" might  give a better sense (just my feeling).

I have come across it  although I doubt if it is particularly common. 

A nice verb though.

[alan gould]

i like "un sportif acharne'" which is a "sports freak" and so by extension i could use it to describe others where an adjective defines the person (and maybe it doesn't have to b an adjective).  

[George Hunt]

Probably a noun  with a strong verbal component ..

https://www.google.ie/search?q=%22un+*+acharne%27%22&ei=jhmlWrXsC8qqU-nZt9gP&start=10&sa=N&biw=1600&bih=769

Seem to be  a few possibilities

"un chaton acharne" is not a "verbal" noun.

https://www.dailymotion.com/video/x5pbb7b