Rico is 9 year-old german collie. It astonished everyone by showing initially that it was able to learn 200 words, but also to make associations of ideas. How is that seen ? Rico is a lucky dog : it has more than one hundred toys ! However when one pronounces the name of one of these toys, it is able to go seeks the good (with however an error rate of 10 %). And for associations of ideas ?
One puts in front of its seven toys, of which one that it doesn't know. This unknown object is named. Then in 70 % of the cases, it will seek the unknown object. (Moreover, he will remember some one month later). In other words, Rico holds the following reasoning : there is among these objects one which I don't know, the word that is said to me is unknown, the object and the word go surely together. It is an association of ideas that human do only after 3 years.
What teaches us Rico then ? First of all, it shows us how we learned how to speak : with time, we named the objects we met, progressively evolution of our needs. But it shows us also another thing : it could be that the dogs used the same process. Since their domestication, the dogs would be thus them also on the way towards the language, according to an academic of Leipzig (Julia Fischer).
But if you are chauvinistic human superiority, reassure you ! Our training of the language remains better bus Rico can learn from words only if the corresponding object is presented to its. The baby can on the other hand learn simply while listening to speak the others. Thus, it does not name only objects, but also of the people, situations, actions, and even of the simple concepts.

To follow the situation, the official site of the Max Planck Institute for evolution and anthropology in Leipzig : http://www.mpg.de/instituteProjekteEinrichtungen/institutsauswahl/anthropologie/index.html