We're going to try at 2, 14 mo IMO is way to early. But you can certainly start with terminologies and asking them if their ready to change their diaper. Repeat words like that, they work on repetition. They might start to recognize when their diaper needs changing.
2/The week after her 4th birthday she decided to start trying pooing in the toilet (with toddler seat). And since then she stopped asking for a nappy, she had few little accidents with poo (only at home), but she’s been doing good, no withholding and no regression for now. I’d say I think it’s easier to train a smaller child than an older toddler, especially if the older toddler has a strong willpower and issues with changes (my daughter doesn’t cope well with any type of change). Younger toddlers are more cooperative but if they’re not physically ready you’ll have a lot of accidents for weeks/months. (Sorry for the long post 😅)
I started before age 1. It's a process not an instantaneous thing. My oldest was using the potty at home around 18 months. Out of nappies at 2. It would have been earlier but we waited for a period of time we were going to be home with him to have consistency as opposed to nappies at nursery and none at home.
We tried at 27 months and he wasn’t ready so going to try at 2.5 years
1/We started when my daughter was 2y2m old because she was dry at night since before she was 2. It didn’t go well. The first 2 days were okay, then she started withholding pee for HOURS. On the 4th day we decided (after talking with hv and nursery staff) to put her back in nappies because she didn’t pee for 12ish hours. We tried again some months after that. She started withholding again. Nothing worked, no matter the bribe. We tried again when she was 3y3m old. She’s stopped peeing for almost 24 hours 🫠 We visited the gp every time and she didn’t have anything physically wrong (no uti etc), it was just mentally. At 3y7mo she started using a toddler seat for peeing with a lot of praise and prices (chocolate, stickers). She had a regression after 2 months, we passed it with bigger prices (bigger stickers, mini figurines etc). But she still wanted to wear a nappy and she was still pooing in nappies. Just before 4yo she stopped wearing nappies but she’d ask for it if she needed to poo.