can duolingo please add, something to do with conjugating verbs (avoir, etre, aller), or maybe different tenses ( perfect tense)
There are a couple of options:
You can use the in-lesson conjugator:
You can also visit the French and Italian Discussion forums. You can get to them from the main discussion page (aka General Discussion forum marked by the heart.)
Here is a guide on all of the different discussion forums, what they are for, and how to find them: https://www.duolingo.com/comment/1254215
In addition, I like to use www.wordreference.com They have an awesome conjugator!
I hope these help!