Dogs can learn the names of objects. The language or relevancy of the name does not matter.
I could teach my dog to roll over and call it banana so that every time I say "banana," my dog takes that as a cue to roll over. I have taught one of my dogs to back around me and call it "git" so that if anyone ever tells her to "Git!" she will make backwards circles around them - which , by the way did not occur to me until after I had taught her the cue.
Dogs can also learn the words that indicate what to do with an object. They can also learn concepts such as left or right. So, for example, I can cue my dog to touch a target on the left.
They can be taught to select an object that is the same as another object and select an object without a name among other objects with names the dog knows.
In addition to learning the names of objects, dogs also learn the names of specific actions, for example "sit" or "come" or lie "down." We can even teach dogs to "copy" what another dog does.
No matter what pitch or volume of voice, a cue should elicit an immediate response from the dog if the dog has been trained by a knowledgeable trainer.