Why not try a Google search of this topic, which has been discussed
many, many times before? Just curious.

We recently lost our Cat in the fall that we had for 15 yrs and turned ferel
to housecat.
He was the most beautiful cat we ever owned~
Now we have a new kitten the is the most beautifull cat we ever owned :)
Patience & Love will do the trick and a nuter or spay and shots will help
alot.
HTH.

Yes.  Sebastian lived in the wild (well the wilds of a defunct roofing
construction site in the city) for more than 12 weeks before he, his
siblings, and his mom were trapped and rehomed.  I socialized him for
2.5 months in my guestroom and gradually introduced him to my (at the
time) two other cats.

The speed of progress will depend upon the personality of the cat, the
age at which socialization begins, and probably a number of other
factors.  There aren't any hard and fast rules.  

I'm not sure "recover" is the word.  Being feral isn't an illness.  It's
a constellation of survival mechanisms which are (for the most part) no
longer needed once a cat is living indoors with people.  Those
mechanisms may take a while to subside.  Some of them may persist.

Sebbie sometimes looks like a regular domestic cat, and at other times
his feral behaviors come front and center.  It depends on the
circumstances.  At 4 years old and 3.7 years living with me, however, he
is very different from the terrified kitten who hid behind the drapes
hissing and who would punch me (with no claws extended) if I tried to
put my hand too close.  While it took him 16 days to initially allow me
to touch him, he now is a total junkie for grooming and loves to have
his belly nuzzled.  Just don't approach him straight on, looking in his
eye, or let him see two hands coming towards him simultaneously!

Priscilla

We've done this twice. Once with apprx. 10-week old sisters, born and
eventually trapped outside where Walter works.

The vet at the time said cats over a couple of months old with no human
contact can be tough to "bring around," but she could tell ours would be
all right. They had been fed by humans, but still were terrified of
being touched. They started accepting pets and coming out to play within
the first three weeks. Two years later -- both love us and love
attention. One has become a basic, chair-stealing house cat, and the
other is nervous and skittery but also a love-bug who craves attention.
They both are wonderful cats, but both will disappear if the doorbell rings.

The other time we took in a feral -- she was apprx. 6 mos. old. She is a
very skittery cat and to this day (9 years later) does not come out
during the day. She still feels the need to hide most of the time, but
is one of the most affectionate and loyal cats I have ever known.
Because I worked so much with her in the beginning, she has decided I'm
her cat-mom. She has to sleep right beside me every night, and
continually wakes me up by rubbing her cheek against my face. She loves
to be petted and scritched. She will never be a lazy, chair-loafing cat,
but she is a joy. Each new breakthrough with her was great, and she now
lives a life that she is comfortable with. She will never march through
the middle of the room without a care, but has her moments of intense
affection. We just have to let her be her own cat.

Hope that helps,

Rhonda