It is generally the case that there is no “natural” connection between a linguistic form and its meaning. The connection is quite arbitrary. We can’t just look at the Arabic word بل ک and, from its shape, for example, determine that it has a natural and obvious meaning any more than we can with its English translation form dog. The linguistic form has no natural or “iconic” relationship with that hairy four-legged barking object out in the world. This aspect of the relationship between linguistic signs and objects in the world is described as arbitrariness. Of course, you can play a game with words to make them appear to “fit” the idea or activity they indicate, as shown in these words from a child’s game. However, this type of game only emphasizes the arbitrariness of the connection that normally exists between a word and its meaning.

There are some words in language with sounds that seem to “echo” the sounds of objects or activities and hence seem to have a less arbitrary connection. English examples are cuckoo, crash, slurp, squelch or whirr. However, these onomatopoeic words are relatively rare in human language. For the majority of animal signals, there does appear to be a clear connection between the conveyed message and the signal used to convey it. This impression we have of the non-arbitrariness of animal signaling may be closely connected to the fact that, for any animal, the set of signals used in communication is finite. That is, each variety of animal communication consists of a fixed and limited set of vocal or gestural forms. Many of these forms are only used in specific situations (e.g. establishing territory) and at particular times (e.g. during the mating season).