"Son casi las siete."
Translation:It is close to seven o'clock.
This is the way DuoLingo works. You learn through trial-and-error, and through using your common sense to construct the rules based on how the language is presented to you in the lessons and translations.
If you want structured, pay for Spanish classes at a learning annex, or buy a university-level Spanish grammar in English.
Of course, the best thing you can do is keep using DL and supplement it with other resources, as this site alone will never make you fluent. Find hispanohablantes in your locale with whom to practice.
I agree with you, but I do find it extremely helpful when duoLingo includes some basic information on the topic in the "Tips" section. The tips section for possessive adjectives was extremely helpful. This site is a great tool but it should not be your only resource for learning a new language. It helps to go to local classes, view instructional videos on youtube, visit some of the reference sites to which other users kindly post links here and even find a Spanish meet-up group.
Actually the correct translation given to me on this was "they're almost the seven" which made NO sense to me. I see the sentence above is completly diferent which does make sense. I just hope that DL does not add just anyones "my answer should have been accepted" to the data base. I am starting to get real concerned with some these.
In Spanish talking about time it seems generally to be short for, say, seven hours - the hours (they) are almost seven or they are almost the seven hours - this is why it is plural (except when you see uno) and why it has las before siete
Unfortunately I think that Duo does bow to pressure when the suggested sentence could be a direct translation. That's the reason why I try hard to have people follow such conventions as Duo seems to have established. I think some users try to translate in many ways until they find an unlikely but possible answer which Duo won't accept.
Yes when DL uses "son casi las siete" to refer to time they do have it right. But first time seeing that, when I tried "they are almost 7" DL's correction was to add the article "they are almost THE 7" as correct translation. This makes no sense to me, sallyann, and a few others. Unless its a dramatic way to say "they are almost the 7 who went on the extreme diet last month" ;-)
Sallyann_54: It appears that you are frustrated, but please sit back and relax and realize that things cannot be translated word-for-word many times. We are talking about two different languages and things will not translate the way we wish they would sometimes. Speaking about the time (la hora) is a very common thing we do every day and it is something that may be needed to study from a book, a live class, an online class or something like that. It definitely is not "the worst translation". It is a perfect translation. Buena suerte.
As a native English (American Midwest) speaker, I think "The hour is almost seven" is perfectly acceptable if a bit formal. It is more commonly said as simply, "It's almost seven". As long as it is clear from context that you are talking about time, the o'clock is often left unsaid.
Here is a good reference for telling time