Days 1 to 7
Two or three lessons a day, ten to fifteen minutes, at the same time each day. Say every sentence out loud before you tap the answer, even the ones you only have to read. That single habit is the difference between a streak and a skill. On day seven, ask yourself three questions: Did I look forward to today's lesson or force it? Can I still use what I learned on day one? Have I actually spoken out loud this week? If the answers are bad, switch to your alternate program now rather than in month two.
Weeks 2 to 4
Keep the daily lessons and add the stories once they unlock; they are the closest thing in the app to hearing the language used by a person. Protect the streak, but do not confuse the streak with progress. Missing one day is fine. Never miss two in a row.
Weeks 5 to 8
Keep the app going and add one free podcast episode a week in your language, at whatever beginner level you can find. Start a two-minute habit: at the end of each day, say what you did today, out loud, in the language, badly. It gets less bad.
Weeks 9 to 12
By now you know whether this language is one you want. If you are still opening the app most days and you want to actually hold a conversation, this is the point to graduate: your alternate program is the program that picks up where Duolingo leaves off, and the habit you built over ninety days is the hard part already done. Before day 90, have one real conversation with a person: a tutor, a language exchange partner, or a friend who speaks it.
Give it the full 90 before you judge it. The difference between people who learn a language and people who don't is rarely the program. It is whether they kept going after the first month.