Anyone who has studied Latin, German, Russian, or a host of other languages knows how to decline a noun, pronoun, or adjective. In many languages, these types of words are inflected to signify the purpose they serve in a sentence or phrase. Words requiring inflections, in all their varying forms, are called declensions. Todecline a noun, pronoun, or adjective is to list all the inflected forms of the word.

When a word is inflected, its form changes slightly, depending on how it is used. Most often, the ending of the word varies to reflect its function as the subject, direct object, or other part of a sentence or phrase. For example, when Julius Caesar addresses Brutus as Brute in the often quoted line from Shakespeare's play, "Et tu, Brute," he is using not a nickname, but an inflected form of the name that is required by Latin when speaking directly to people.

Although most speakers of English are unaware of it, English also has declensions. The roots of English are in the Germanic languages, and Old English, like modern German, required different forms of its nouns, depending on how they were used. Over the centuries, the grammar of the language has become simpler, so that today the only variations of most English nouns are the singular, plural, and possessive. We no longer have to worry about the nominative, accusative, dative, or other forms of nouns. Adjectives no longer have any inflected forms at all.

There is one area, however, where more complex inflections are still required. English personal pronouns have three inflections related to the purpose they serve in a sentence or phrase: nominative, accusative, and possessive. For the first person singular, these are I, me, and mine, respectively. The nominative form is used when the pronoun is the subject of a sentence, representing a person or thing carrying out an action. The accusative form is used when the pronoun is the object of a sentence or a preposition, representing a person or thing that is affected by an action.

Sometimes we confuse the subject and object forms of the personal pronouns. There are several reasons for this. One reason is that over the centuries, the rules have been relaxed so that in some places where the nominative form is appropriate, the accusative form is used. For example, so few people say, "It is I," that "It is me," has become acceptable. Another reason is that the second person singular and plural (you) and the third person singular neuter (it) have the same form for both the subject and the object. It is not always easy to tell whether you goes with I or with me. Finally, it is rare these days for children to receive a complete explanation of the inflections of English personal pronouns.

One result of this confusion is that we increasingly hear people say "Between you and I," instead of "Between you and me." That the former is a problem is evident if we replace you and I with the equivalent form of the first person plural, we. Nobody ever says "Between we." Many years ago, students were warned against using this construction. It was called hyper-correction because many people incorrectly applied the only rule they remembered from grammar classes: "You should say, 'It is I,' not 'It's me.'"

We do not see incorrectly inflected personal pronouns as often in writing as we hear them in speech, although this fact may owe more to the diligence of editors than it does to the care of writers. In any case, you should take care to use the appropriate form for the personal pronouns you use in your writing. As a review (in case you missed it in school), the nominative and accusative forms of English personal pronouns are listed below.