Answers
Dec 01, 2014 - 09:03 PM
"Venir de" is translated as "just" because there is no better way to describe an action made in the recent past in English. When you add "juste" to "venir de partir" you putting an emphasis on how recent it was. For example "Je viens juste de manger" to say that you just finished your meal moments ago whereas "Je viens de manger" could mean that you finished your meal a couple of hours ago.
Dec 01, 2014 - 09:49 PM
In English the perfect tenses show an accomplished fact in relation to a particular point in time in the present, past, or the future. For example: When I arrived, he finished his dinner (past tense). Now this: When I arrived, he had finished his dinner (past perfect tense). In the first example, the statement suggests that AFTER I arrived, he finished his dinner, whereas the past perfect tense makes it plain that by the time I got there he had already finished his dinner.
Dec 03, 2014 - 03:53 PM
In my opinion, It may sound redundant but it is emphasizing the timing of the action. Saying "il vient de partir" may have been now, 10 seconds ago or 15 minutes ago. "Il vient juste de partir" relates more to a very short time.