Grammatical Case in European Languages

The Latin language itself is an excellent resource to understanding basic concepts of language.  One fundamental aspect of language that Latin illustrates in particular is the concept of grammatical case.  Every language must somehow express grammatical case in order to form the simplest of sentences.

Contemporary European languages primarily use word order to indicate case.  They also rely from time to time on inflections or suffixes to indicate case.  In Latin, however, case is indicated entirely through inflections.  Because the grammatical case of each noun and adjective in Latin must be identified with an inflection, understanding grammatical case completely is essential to understanding Latin.   

In the following English example, the grammatical case of each noun is expressed by word order.  Word order establishes the subject as the cow and the object as the circle: 

The cow is in the circle.

If the nouns in “the cow is in the circle” were switched to “the circle is in the cow,” the meaning of the phrase is completely changed.  The subject is now the object of the sentence.  That is grammatical case at work. 

However, languages such as German and especially Latin make use of inflections rather than sentence order primarily to express grammatical case, and as such the rules on word order are much looser.  In the case of Latin they are almost non-existent.  Just by adding a suffix to one of the nouns, the subject and object can be identified.  “The cow is in the circle” might be said like this in Latin:  ‘circle(obj), cow is in’ or even ‘in cow is circle(obj).  In these examples, “(obj)” substitutes for a suffix which informs that the noun is the object.  It is word order in English which establishes the grammatical case of the circle; that it is the circle that the cow is in, when someone says the cow is in the circle.  Suffixes, or inflections can define the grammatical case just as easily. 

In fact, the genitive case can be expressed in English by both word order and inflection: 

‘the car of the man’

or

‘the man's car’

This chart I picked up helps conceptualise further what grammatical cases are and how they are expressed in English and Latin:

source: http://en.wikibooks.org/wiki/Latin/Lesson_2

This is a good quick look at Latin grammatical case and noun declension:
http://www.math.osu.edu/~econrad/lang/ln.html

This extensive article is excellent in its presentation of grammatical case and how nouns in Latin are inflected to show their case:

http://en.wikipedia.org/wiki/Latin_declension

This five page series looks at the 5 declensions of nouns in depth:

http://en.wiktionary.org/wiki/Appendix:Latin_first_declension

This article looks at declination of adjectives
http://en.wikibooks.org/wiki/Latin/Lesson_1-Nominative#Adjectives_in_Latin

This online grammar study book is excellent as an introduction to Latin and Language concepts itself.

http://en.wikibooks.org/wiki/Latin/Lesson_1