The pronoun I in the statement but I know him is emphatic, as are the last two pronouns you and him in verse 28. The use of the pronoun I is optional in a Greek sentence, since the verb endings indicate person and number. The pronoun is sometimes added for the sake of emphasis, and I at the beginning of a sentence or clause (as here) is particularly emphatic. In this manner a strong contrast is made between you in the last clause of verse 28 and I in the first clause of verse 29. This emphasis and contrast are immediately evident, even though there is no conjunction, such as “but,” connecting the two clauses. For the English reader, the emphatic contrast may be missed in a strictly literal translation, and so Good News Translation add the conjunction but at the beginning of verse 29 to indicate the contrast, as Jerusalem Bible and Moffatt also do.

The Greek verbs translated sent in this verse and in verse 28 come from different verb stems, but there is no difference in meaning. Essentially the same formula (I know him) also appears in 8.55 and 17.25.

In some languages the rendering of come and sent may suggest a contradiction, since the first term would suggest the complete action of arriving, while a term for sent might suggest merely the process of sending someone forth. Therefore it may be more satisfactory to reverse the order, for example, “because he sent me and I have now come from him.”

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 .