"I just finished a letter."
Translation:Je viens de terminer une lettre.
I don't think so, because "justement" means something else than "juste".
"J'ai justement terminé une lettre" (pls note the position of the adverb, which can also be put at the end of the sentence for the same meaning) could be a comment made in a situation like this:
- je pense qu'il faut donner des nouvelles à Paul (I think we should send news to Paul)
- j'ai terminé une lettre, justement (I have just finished a letter, for that matter).
So, "je viens (juste) de + infinitive" means "I have just finished / I just finished"
I would not generally question your judgment but on this particular point I think it might be interesting to revisit this subject more deeply.
Juste / tout juste / justement may be found as equivalent components in virtually the same phrases.
Justement means "precisely", particularly in very defined contexts. But so does "tout juste" and "juste". "Juste" and "justement" may have an entirely different meaning. But "Justement" is, as you know, only the natural extension into an adverb.
(i) "Je viens justement de recevoir une lettre" ( Exploring the French Language, Lodge, A., John Wiley & Sons, 1997, p.26).
(ii) "Je viens juste de recevoir une lettre" (http://www.linguee.fr/francais-anglais/search?source=auto&query=Je+viens+justement+de+finir+une+lettre).
(iii) " Au fait, je viens tout juste de recevoir une lettre pour le moins cocasse" ( http://www.linguee.fr/francais-anglais/traduction/je+viens+tout+juste+de+recevoir.html).
I don't in the least want to complicate matters. Still, I find this type of "mise à jour" interesting. I just wanted to underpinn the point that in some cases you can have those words used in the same manner - I gave three legitimate examples of the Duolingo English phrase translated with those terms: "juste/ tout juste/ justement. The other options cannot offhandedly be classified as wrong. All of them may be utilized out of a chronological context merely by expressing "correctly, rightly or precisely". To make things a little worse I might point out that this is not merely a rhetorical exchange of opinions in a French learning system. The French speakers themselves have the same doubt. In other words for "very native" french and seemingly "very worried" with their language french people, they argue that those different words come to the same estuary. Take a look:
"ABC de la langue française : forums » Réflexions linguistiques » Juste ou justement. [http://www.languefrancaise.net/forum/viewtopic.php?id=673]
Most of the forum arguments are from 2005. It was updated last year (2016). " Et rien ne semble cassé."
The lesson here is very basic: you are taught the French way of expressing the near past.
"je viens de finir une lettre" = I (have) just finished a letter.
The French near past is constructed with the verb "venir", just like the near future is constructed with the verb "aller".
It can live without "juste", but the English near past cannot be understood if you don't add "just".
If you add "juste" in a French sentence in near past, it is a bit emphatic and it stresses that the action was completed in a very near past, nothing else.
That is all there is to understand at this point and the fact that "juste" or "justement" have several meanings in context does not affect this lesson.
Viens + de + infinitive implies the recent past, not the present tense, like Sitesurf has explained in the discussions above. Also, contrast this to aller/va which the French use to describe the near future. They are both used in the present tense conjugation, but imply near future.