Translation:She has been waiting for this moment for a long time.
This sentence was given to you to illustrate the fact that the English construction with the present perfect + a date or a duration (since yesterday, for a long time) translate in French with a simple present.
If you place the action in the past, this is what happens : "she had been waiting for this moment for a long time" = "elle attendait ce moment depuis longtemps".
In addition, the English form of the verb is continuous (be + verb-ing), which does not exist as a verbal form in French. Therefore, in Duolingo, all continuous present forms are translated in simple present (is waiting -> attend) and continuous past forms in imparfait (was waiting -> attendait).
If you use pluperfect "she had been waiting" it means that the action was entirely in the past, so in French, you translate it by the imperfect: "elle attendait".
If the English sentence uses since + present perfect, the French uses depuis + simple present.
-present: she has been waiting since yesterday: elle attend depuis hier
-past: she had been waiting since the day before: elle attendait depuis le jour précédent.
Thanks for explaining this, I was confused. If I want to use the present perfect generally, can I use the simple past tense or do I continue wiht present? par exemple: je suis très occupée car je travaille dur (or j'ai travaillé dur) - I am busy because I have been working hard. Many thanks.
The sentence doesn't sound quite right to me in English. "I am busy because" in English implies something happening now causing you to be busy. To then say "have been" doesn't seem grammatically correct in English. I would have said "I am busy because I am working hard" or "I have been busy because I have been working hard". "Have been" is present perfect, not simple past.
I think you still need to refer to what Sitesurf said about the tense. "Elle attend ... depuis longtemps" is something that the subject of the sentence is in the process of doing right now, not something she has already done. So, to make a long story short, Duolingo took a heart from you because you used the word "awaited" instead of "awaiting" - you might try "she's been awaiting this moment..." and see if that works better for you.
If you complain at a reception desk "I have been waiting since a long time" you will be understood but it will be clear that you are not a native English speaker. "I have been waiting for a long time" is correct. Alternatively "I have been waiting since 10 o'clock". "Since" always refers to an identified moment in the past.
Its a clue to the answer as I have learnt. The statement talks about something ongoing. So "depuis" is the key here to understand what Sitesurf mentioned with the construction of the French present tense to match the English present perfect (Sitesurf explains it well above). Or look at it this way, if the action was based in the past and has been completed, "pendant" would have been used, indicating also that the past tense verb for waiting should be used - "attendit". If it was a future action then "pour" could be used with "attendra" and so on. That's my understanding.
You need to read the entire thread carefully. The French often use the present tense when making reference to the past - when this is translated into English anyway. I cannot speak for other languages. But the tense, in the English translation, changes through the use of the preposition "depuis". See here for more information - http://french.about.com/od/grammar/a/depuis-pendant-pour.htm.
elle attend ce moment depuis toujours (correct) = she has always been waiting for this moment.
elle attend ce moment pour longtemps does not mean anything, I'm afraid:
- elle attend ce moment depuis longtemps = she has been waiting for a long time (past to present)
- elle est en prison pour longtemps = she is in jail for a long time (present to future)
Longtemps is more "a long time" - see here. Depuis, alone, does mean "since", in the sense of an action beginning (and continues) within a specified date/time period: "... since 2014... 5pm".
"For" is used where the period referred to is unspecified. So here, "... a long time" is unspecific (but may still be continuing).