Reddit reviews Practice Makes Perfect: Intermediate German Grammar (Practice Makes Perfect Series)

As of right now I have, German Grammar Drills,Intermediate German Grammar, and German Pronouns and Prepositions. I plan on buying the rest sometime this mouth. I'm even going to get them in some other languages too.

I taught myself german while I was in highschool and I am still teaching myself in college (almost 4 years now). What really helped me was to make a reference notebook as I learned things. In it I had conjugation charts, article charts, noun case charts, sentence structure references, and some specific irregular verbs conjugated out. In the back I had a list of common words I had to remember and a list of irregular verbs with their rules. There's tons of good references for conjugations and such on google images if you don't feel like writing and drawing it all out on your own. It really helps you see the patterns which will help you form your own sentences on your own easier, since imo Duolingo doesn't do a great job teaching you the speech and grammar patterns and just throws it at you in a trial-and-error learning method.

Along with my reference notebook and duolingo, I got some inexpensive grammar workbooks from amazon. There are plenty of free online worksheets too, but I like having everything in one place and it basically gave me a curriculum to follow. I worked on this pronouns and prepositions one and this verb tense one simultaneously going chapter by chapter, then after finishing them and a lot more duolingo moved on to Intermediate Grammar. This series has so many options, but these three I felt were more difficult and not as well-covered by Duolingo, which definitely covers a ton of vocabulary and conversational grammar. here may be some overlap, but practice is practice and it will only help you.

I have not stopped using Duolingo either. Always do the speech prompts during practice! Pronunciation is one of the hardest parts to learn, since you have to make completely new mouth shapes. I didn't have anyone to practice speaking with so I practiced by reading passages and repeating the questions and answers on Duolingo. The Stories feature on desktop duolingo is great for this!