The word thou ( in most dialects) is a second person singular pronoun in English. It is now largely archaic, having been replaced in almost all contexts by you. Thou is the nominative form; the oblique/objective form is thee (functioning as both accusative and dative), and the possessive is thy or thine. Almost all verbs following thou have the endings -st or -est; e.g., "thou goest". In Middle English, thou was sometimes abbreviated by putting a small "u" over the letter thorn:

Originally, thou was simply the singular counterpart to the plural pronoun ye, derived from an ancient Indo-European root. Following a process found in other Indo-European languages, thou was later used to express intimacy, familiarity, or even disrespect while another pronoun, you, the oblique/objective form of ye, was used for formal circumstances (see T-V distinction). In the 17th century, thou fell into disuse in the standard language but persisted, sometimes in altered form, in regional dialects of England and Scotland, as well as in the language of such religious groups as the Society of Friends. In standard modern English, thou continues to be used only in formal religious contexts, in literature that seeks to reproduce archaic language, and in certain fixed phrases such as "holier than thou" and "fare thee well". For this reason, many associate the pronoun with solemnity or formality, connotations at odds with the word's history. Many dialects have compensated for the lack of a singular/plural distinction caused by the disappearance of thou through the creation of new plural pronouns or pronominal constructions, such as y'all, yinz, youse, you lot, and you guys. These vary regionally and are usually restricted to colloquial speech.

Grammar

Because thou has passed out of common use, its traditional forms are often confused by those attempting to imitate older manners of speech.

Declension

The English personal pronouns have standardised declension according to the following table:

===Conjugation

In the subjunctive and imperative moods, the ending in -(e)st is dropped, although it is generally retained in thou wert, the second-person singular past subjunctive of the verb "to be". The subjunctive forms are used when a statement is doubtful or contrary to fact; as such, they frequently occur after "if" and the poetic "and".

If thou be Johan, I tell it thee, right with a good advice . . .;Middle English carol:

If thou be Johan, I tell it the
Ryght with a good aduyce
Thou may be glad Johan to be
It is a name of pryce.