In the Netherlands, the personal pronoun gij and its variants are now mainly used in religious context and are considered archaic. In Flanders and the southern Netherlands, gij is still commonly used as the second-person singular in colloquial language but in formal language, it is not used unless the referred second person is the "god" or the "king".
The best translation when used in archaic contexts would be thou; when used in Flanders, it would typically be you (singular). Unlike in English, gij usually takes the same verb form as jij except when there is inversion or with some irregular verbs or in the past tense. Compare heb jij dit gedaan? versus hebt gij dit gedaan? (have you / hast thou done this?). Also: jij zal versus gij zult (you shall/will / thou shalt/wilt), jij bent versus gij zijt (you are / thou art), jij vloog versus gij vloogt (you flew / thou flewest) etc.
1) Not as common in written language. 2) Inflected as an adjective.
3) In prescriptivist use, used only as direct object (accusative). 4) In prescriptivist use, used only as indirect object (dative). 5)Archaic. Nowadays used for formal, literary or poetic purposes, and in fixed expressions.