Many dogs – even some not well-trained ones – can perform action-related commands, such as sit, down and stay. But there are some dogs that can remember the name of hundreds of toys – ball, squeaky duck, bone, bear. And it’s not that they memorize a lot of different names – a study by Hungarian behavioural researchers shows – but that they can remember these names for at least two years, demonstrating that it is not just humans who can memorize words over the long term. As long-term memory plays a major role in language development, the memory capacities of animals for names and their categori…