Although animals lack vocal cords and speech organs like humans, some animals have vocals of their own. Wild apes are known to talk to each other to make the other aware of a possible danger. Animal language does not have discreteness like human languages. In human languages, discrete units are combined together to make a new word with a meaning. So signs or sounds, in animal language, cannot be combined to form another sign or sound, which means something. But researchers have proved it that the animal language does meet certain requirements. But the validity is still disputed upon by many and that is the reason why animal language hasn't been given the status of a true language.
People have questioned the practice of great ape language. The researchers try to understand whether the usage of this language aid the animals to solve the problem better. Also, whether the teaching experiences with a primate can be of use when human children are taught. This is because, there is without doubt a difference in the ability of the animal and a human, while they may be similar at some level. Some say that the apes do not actually understand the language, but instead do a clever trick to get a reward. Also some researches say that the signed gesture do not make a grammatically right sentence. The arbitrariness is sometimes missing, that is, there is no clear relationship between the signs or sounds.