Hello Rena,
My two girls were potty trained by 1 and a half, toilet trained around 6 months after this.
I read all the books about training in 5 days, but realistically, with twins, that is one hell of a feat! it took me around 2 months of hassle overall.
Me, my approach was simple, remove the nappies...started in summer and let them run around with nothing on at all in the garden. Yes, they wet and messed in the garden!! Brought the pottys but they hated them. Took them to Mothercare and brought the potty chairs and they loved them. They sat in them for hours. While they were using them as seats, the movements occurred with no stress. I rewarded them by taking them out to buy 'big girl pants'. They chose the pictured ones.
I refused to put them in nappies or pull up pants because as soon as I did they stopped using the potty chairs. Not surprising really, as I was giving them mixed messages...
They had multiple accidents, ones and twos! But because they were in pants, they got upset at the feeling of wet or messy underwear and would ask to have them changed. Oh! and didn't we have some messy ones!!!!
For each pair of pants they spoiled (I would throw them away) and tell them if they continued I would not buy anymore...
Strangely enough, this worked because they hated to see their favorite character pants go in the bin....they would hassle me, well before wetting or messing their pants.
Because the potty chair had a little removable seat, they got used to taking it to the toilet themselves and emptying it...
The chairs are highly recommended. If we went out anywhere, I would put throwaway baby change covers in their car seats and buggies and carried around 10 pairs of pants!
I also would sit them down on their potty chairs about 20 minutes after any food and read books to them. Again, this proved to be fruitful.
However, not to forget all children are different, so it may be a case if you have tried and it has not worked, you are trying too early...the older they are the easier and quicker it is suppose to be..
Nik