I have only ever used the paid version of Duolingo that my husband got for me. I have no idea if the basic version works, so keep that in mind.
There are three things in Duolingo that really advance language learning. They are the chatbot, the Legendary level, and Match Madness.
Chatbot
You need to have at least one conversation with the chatbot every day. Ideally, you’ll have two. Here’s what’s important: don’t let the chatbot control the conversation because if you do, you’ll end up having the exact same conversation every day. To make it useful, you have to initiate. When the chatbot says, “hi, how are you?” Don’t respond with, “I’m fine, how are you?” You already know how to say it, so what’s the use of doing it again? Instead, start your own conversation on the basis of what you learned in the day’s lesson. For instance, if you learned about birthdays, say “It was my birthday last week. To celebrate, I went to my favorite restaurant with my family. We ate my favorite dish which is fish with vegetables.” It doesn’t matter if it’s true. Your goal is not to provide correct information to the chatbot but to practice.
Legendary level
After you complete each batch of exercises, you can press on it again and have the option to do a sort of a test on them. That option is called Legendary. It’s great because often it asks you to translate sentences into the target language. You get up to 20 sentences that you have to translate on the spot. Specialists in foreign language teaching tell us that translation exercises are bad for beginner and intermediate level students. That is stupid, however. Translation exercises are great. I wish Duolingo had more of them and didn’t limit them to the Legendary level only.
Match Madness
This is a contest-type activity where you have to match words in the target language with their translations. To keep advancing through the levels, you have to find translations at an increasing speed. This is excellent for improving your vocabulary.
The chatbot, the Legendary level, and Match Madness are the hardest activities on the app, and many people avoid them. But these are precisely the activities that move your knowledge of a language from a passive to an active mode. Both modes are crucial for language learning but if you are stuck in passive, you’ll never speak.