It can be difficult remembering all these rules. Sometimes I have to change my focus and then come back to it at a later time to wrap my head around it all. As a native English speaker, it makes me realize also how difficult English must be to learn as a second language.
I appreciate these discussion boards, because we can help each other and also see we are not the only ones with certain questions. Duolingo has been a great blessing.
Something I have found that's also been very helpful is the language diary challenge promoted by @joyoflanguages on Instagram. Each day, we are to write or say something about our day. It's been very useful, because I'm talking about daily life, so I'm also building vocabulary more about my personal daily life. I choose mostly to do videos, because I find it's so much easier to read and write, than to speak.
With reading and writing, you have more time to think and check your work. Speaking takes away that extra reaction time.
Speaking it on video is pushing me out of my comfort zone. Plus, it is inspiring to others. You can find me on Instagram @sivapriyama