They answered him is literally “they answered and said to him” reflecting a Semitic Greek style that is redundant in English.

Our father is Abraham must be rendered in some languages as “our forefather is Abraham” or, possibly, “our forefather was Abraham.” Since, however, the term Abraham might be understood as the given in formation, the components of this equational sentence may be reversed in some languages as “Abraham was our forefather.”

In Greek, conditional clauses (“if” clauses) may be so stated as to indicate that the condition is either true or is contrary to fact. Sometimes these clauses are greatly mixed with the result that an even greater vividness is achieved, as in the Greek text followed by Good News Translation. Here the Greek conditional sentence is of a “mixed” type, so that the force is If you really were Abraham’s children, rather than simply “if you were Abraham’s children.” Two important Greek manuscripts have an imperative in the conclusion of this if clause, which results in the reading, “If you are Abraham’s children, do the same works that he did.” Moffatt accepts the imperative as the better choice of text, and this possibility is given by Good News Translation and New English Bible in a footnote as an alternative rendering. However, it is more logical to assume that the imperative was introduced by ancient scribes who attempted to do away with the grammatical difficulties of the mixed type of conditional clause. For this reason the UBS Committee on the Greek text gives its primary support to the reading followed by Good News Translation, though evaluating their choice as “C,” indicating considerable doubt regarding the original reading of the text.

To indicate clearly that a condition is contrary to fact, it may be necessary in some languages to employ a supplementary clause, for example, “If you were Abraham’s children—and obviously you are not—you would do the same things that he did.”

You would do the same things that he did may be translated “you would work in the same way that he did” or “you would behave as he behaved.” It is obviously necessary in this type of expression to avoid a term which would apply merely to physical labor. Customary behavior, rather than physical labor, is meant in this context.

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 .