a little help
noe that i have completed my Spanish tree i was wondering how do i do a reverse tree?
It's simple: just turn your screen 180° degrees /s.
If you haven't already found it by now, direct link: https://www.duolingo.com/course/en/es/Learn-English-Online
On top just click the button to switch to the course.
Personally, I find reverse trees useful. I also find forward trees only grow more useful having finished them (namely, it seems there are more translations into target language). Reverse trees are good for the lessons, since the translations will almost all be into your target language, but they don't seem as good to me for "in depth" reviewing. The strengthening exercises will include super simple grammar exercises in English and multiple choices where you'll know the the answer just because only one option makes any sense, not even having to read the original Spanish.
So, in short, I'd recommend dividing further Duolingo Spanish effort between the reverse tree and reviewing/strengthening your forward tree.