why can't I potty train my 1 year dog?

How should I know when you haven't said what you've done or tried?

because you are not consistent enough.all dogs at all ages can be potty trained.everytime it starts to do its business inside the house, pick it up and take it outside, even if it is still halfway through, IMMEDIATELY.when you get it outside and it finishes, praise her a lot.take her outside regularly (maybe 4 times a day or more if nessecary) so that she doesnt have the chance to go inside.you MUST be consistent and do this every day, and every time she needs to go, or it just wont work..

You can you just have to keep on trying its not like its too old cuz its just 1 year old. here's what you should do : whenever it goes no no in the living room or where ever you take it to the spot and you just repeat No NO NO NO if that doesn't work then Sorry. :-)