Im not english speaking.
What is a feral cat?

There may be other definitions but from where I come from a feral cat is house cat that has been turned loose and becomes wild. Sort of like a house cat that has gone wild. Not sure if others have a different definition but this is what I have always defined as a feral cat.

Feral Cat ... is one that is born wild. Descended from domestic cats ... but not a Stray or abandoned cat.

http://www.bing.com/reference/...p&fwd=1&q=feral+cats

Thanks, its what I thought. A wildcat.

A feral organism is one that has escaped from domestication and returned, partly or wholly, to a wild state

just like a feral hog...click this link for definitions

Usually feral is accepted as "at one time, domestic, but gone wild"

Now commonly used to describe a "Returned to Wild" animal but not really correct usage.
A Feral cat is totally different to an ex-domestic, I've got a couple of each. The ones Born Wild then tamed are far more alert and aggressive than any house Cat.

I have a cat, Charlie, that was a feral I got when he was still a young kitten. He's as tame as can be around me my wife and our other animals but hyper alert, not real aggressive but likes to play a lot. There are very few other people he will even show himself too. He was so young when we got him I figured he wouldn't have any feral left in him. There are two people to date who can come in the house and he's comfortable with them. Very odd, not sure what he see's different in them over others.

I fed a feral tom until we became buds.
Brutus was basically an attack cat.

Like my Gard Cat "O2" ... he figured he was real tough till a little girl came RIGHT UP to the window sill that's his forward post and SMILED at him, she had absolutely NO TEETH! Freaked him right out.
Funny as heck, he hid in the garden for ages.