The study of phonology is the study of the patterned interaction of speech sounds. A fairly obvious observation about human language is that different languages have different sets of possible sounds that can be used to create words. For example, the sound 
is found in languages like Navajo, Coushatta, and Secwepemc, but not in English, Spanish, or French.
When one language borrows sounds from another language, the borrowing language must often adapt the words to fit the set of possible sounds in its inventory. For example, observe the following data, which illustrate borrowings into Hawaiian from English:
| English | Hawaiian | |
rice  |
 |
|
wine  |
 |
|
brush  |
 |
|
ticket  |
 |
|
Albert  |
 |
The data in the table above show that Hawaiian alters the English words in order to fit them into the possible inventory of sounds. For example, Hawaiian does not have the sounds 
, 
, or 
. Whenever the English word contains one of these sounds, it is replaced with the sound 
(eg. 
> 
). Also, Hawaiian does not have the sound 
. Whenever the English word contains this sound, it is replaced with the sound 
(eg. 
> 
). Similarly, the sounds 
and 
are replaced with 
and 
, respectively.
The following chart shows the sound inventory of Hawaiian:
However, besides the replacement of one sound for another, there are other differences between the English and Hawaiian words. In the Hawaiian forms, vowels are inserted that do not exist in the English forms. For example, you may note that in all the examples, a final vowel is added in the Hawaiian forms (eg. > 
). Also, a vowel is inserted whenever there are two consonants side-by-side in the English forms ( > 
). Finally, in the name Albert, there is a consonant added at the beginning of the word ( > 
).
This suggests that Hawaiian not only has restrictions on what sounds can occur in the language, but also conditions on how those sounds can be used in the formation of words. Based on the data above, we can propose three conditions on the interaction of sounds in Hawaiian:
A thorough study of Hawaiian words would show that these restrictions are not just restrictions on borrowed words, but also on all words in Hawaiian.
One of the goals of phonology is to describe the rules or conditions on sounds and sound structures that are possible in particular languages.
Tohono O'odham
Another major goal of phonology is to account for the similarities among human languages. That is, even though the different languages have different sets of sounds and different ways of arranging and patterning those sounds, there are a number of similarities across human languages. The following are a few of these similarities, often called universals:
There are also some near-universals, such as the following:
, except Hawaiian
One of the goals of phonology is to define the space of possible sounds and sound structures that all human languages draw from.
The exercises on the following pages are designed to illustrate characteristics of phonological analysis.