I finished the skill tree.
Unfortunately I do not feel as fluent as I would have hoped. It will need a lot more use and practice but I will try to keep that up. For the record my 148 day streak does include 3 or 4 streak freezes. I did not want to lose momentum.
Congratulations. In the very end you will learn to speak fluently simply by speaking. That's the part of the language learning process Duolingo and all of the other websites is anything but strong. But the foundations are laid now.
Just start to speak, when the opportunity is there, then you'll get some positive feedback, then you'll continue, you'll make some mistakes, you'll realize the mistakes, improve your skills and then you'll go on.
Have you been learning Spanish from scratch with no previous knowlege in Romance language?
Have you been practicing Spanish with other resources besides DuoLingo in parallel?
I am trying to do the 100 days www.50languages.com MP3 audio course (including Memrise, words not ordered within multiple day levels) and Memrise PT BR Basic, PT BR 1-7 (and other user created).
There is one big Spanish listen sentence = typing Memrise course, which I found by accident.
Hopefully I refind it and can link it.
I sure can tell you that I won't finish my Portuguese tree before end of this year, probably Q1/2018.
So it will be more than a year for this tree.
And as I am re-learning PT "Present2 verbs" level on the Memrise-DuoLingo course, I have the feeling that I learned not that much on DuoLingo when I finished that skill the first time (not on one day) :-)
It already takes me multiple days to re-learn those 73 words; I make many errors, can almost not complete the green learning bars (6 steps) for most of the (more difficult) words and when I review the learned words on Memrise 12-24h later, I sometimes still do not know them.
It simply was not possible to re-learn those 73 words in one batch easily with the "infinite learning" user script.
The same happened to me with some previous verb/adverbs skills = Memrise levels, where it took a little bit longer after actually completeting the DuoLingo skills.
So the question is:
When it took you only 5 month to complete the full tree, how well do you remember all the learned words, tips & notes (web), how many reviews have you taken?
I guess we should not even start talking about all the grammar including tenses and verb conjunctions? :-)
DuoLingo's skill strength bars and words decay works quite different than Memrises more short-term 3-6/8, 12h, 24h++ review algorithms, where it allows you to force to learn / review your words, until the review intervals get longer (when you got the words right).
Memrise especially allows you to practice your weak words you did not know well in reviews and there is even a difficult words button, if you use the Pro membership (which I don't).
It counts words as difficult which you repeatedly answer wrong in the 6 learning steps or reviews.
I do not know if there are more advanced features in Anki.
I had seen a different (more detailed) button answer rating on www.language101.com and the Spanish test course.