"Jeg gør det selv"
Yeah, I have my own cats! I don't need yours...
how to say in danish `i do this by my ownself´
my own cats as opposed to whose?
Couldn't this be 'Jeg har sine egne katte'?
No, 'sine' is used when you're talking about someone else, fx. "Hun har sine egne katte" -> "She has her own cats".
almost sounds like in my German dialect :-)