Jesus answered is more literally “Jesus answered him.”
I have always spoken publicly to everyone is more literally “I have spoken publicly to the world.” Good News Translation includes the adverb always, which carries through the force of Jesus’ words. Publicly translates the Greek word first used in 7.4 (see also 7.13,26; 10.24; 11.14,54; 16.25,29). Have always spoken publicly may be rendered in some languages “have always spoken to that everyone could hear.” The converse of this statement is given negatively in the last sentence of this verse, I have never said anything in secret.
In this context “the world” refers to everyone what Jesus had come in contact with; New American Bible reads “to any who would listen.”
All my teaching was done in is literally “I have always taught in….”
The word for Temple is the same word used in 2.14 (see there). It refers to the entire Temple area. This same word is also used in 7.14,28; 8.20; and 10.23. In the synagogues (Moffatt, Goodspeed, Revised Standard Version, “in synagogues”) is literally “in synagogue” (New English Bible). Since Jesus taught in more than one synagogue, it is more natural in English to use either the plural or an implied plural (note, for example, New American Bible “I always taught in a synagogue or in the temple area”).
Many commentators believe that the clause where all the people come together is a comment of the Gospel writer, since it would be an unusual thing for Jesus to be saying to the High Priest. However, in translation, it may have to be presented as a word of Jesus. Come together would be more appropriately rendered “meet” or “meet together.”
I have never said anything in secret is more literally “… and in secret I said nothing.” This same contrast between “in the open” and “in secret” occurs in 7.4, which Good News Translation renders No one hides what he is doing if he wants to be well known.
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 .