Thomas answered him is more literally “Thomas answered and said to him,” once again reflecting a Semitic formula for introducing direct discourse.

Thomas’ response My Lord and my God is the rendering in almost all translations. In order to indicate clearly that Thomas addressed Jesus as both Lord and God, it may be necessary to introduce his statement by “Thomas spoke to Jesus as,” “Thomas addressed Jesus as,” or “in speaking to Jesus, Thomas said.” In some languages it may be more appropriate to translate “Thomas answered him. You are my Lord and my God.” In languages in which the use of the conjunction and would imply two individuals, it may be necessary to translate “you are my Lord, even my God.” In certain languages one cannot possess such terms as “Lord” or “God.” If so, it may be necessary to translate “you are the one who rules over me, and you are God whom I worship.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .